Moving, hanging and removing wall pictures on Shabbos:[1
The need for moving a wall picture on Shabbos can come up in various scenarios, most commonly in the event that it became tilted out of place. Whether moving a wall picture is permitted on Shabbos grapples with the question of whether doing so transgresses the Muktzah prohibition. An additional related discussion is with regards to hanging, or removing a wall picture to or from the wall on Shabbos. Although it is a given that it is forbidden to hammer a hook or nail into the wall on Shabbos for the sake of hanging a picture, or any item, nonetheless, if the hook or nail is already in place the question is raised as to whether the picture may be placed onto it on Shabbos, such as in the event that it accidentally fell off, and you would like it to be replaced. Likewise, the question is raised as to whether one may remove the picture from the wall on Shabbos, such as to show it to an individual. Both of these cases touch upon the question of whether doing so transgresses the building or destroying prohibition, in addition to the Muktzah question already raised. The following is the ruling on this subject:
Is a wall picture Muktzah? Some Poskim imply that all wall pictures which are already established on the wall and are particular to not be moved lest damage occur to them [i.e. are expensive], fall under the severe Muktzah category of Chisaron Kis and hence may not be moved on Shabbos [in the regular way]. Other Poskim, however, rule that wall pictures are never considered Muktzah under any category, even if expensive, and hence may be moved even regularly. Practically, according to the rulings of Admur, it is implied like the the latter opinion. According to all opinions, even if the pictures were to be viewed as Muktzah, it is permitted to move the picture with an irregularity, such as an elbow, or back of the hand, and the like. [Thus, if a wall picture became tilted out of place one may move it back into place, and even according to the stringent opinion, it may be straightened back into place using an elbow and the like.] Likewise, inexpensive pictures which one is not particular against damage occurring to them, and removes and replaces them onto the wall, as he wishes, is not considered Muktzah accoridng to any opinion.
May one place a picture on the wall on Shabbos: It is permitted on Shabbos to hang pictures on a hook or nail that is already sticking out of one’s wall. This applies even if one plans to have the picture permanently remain there. [This applies even according to the stringent opinion above who prohibits moving a wall picture on Shabbos, if this is the first time that the picture is being placed up. This, however, only applies if the picture is simply hanging on a hook or nail and can be easily removed by simply lifting it up. It is however forbidden to fasten the picture onto the wall in a way that it becomes difficult for it to be removed, such as through the use of screws, or adhesive tape. It goes without saying that it is forbidden to initially hammer a hook or nail into the wall on Shabbos. Furthermore, some are stringent not to place any picture on a wall on Shabbos, even if it will hang on a mere nail.]
May one remove a picture from the wall on Shabbos: According to the approach that wall pictures are not Muktzah on Shabbos, it is permitted for one to remove from the wall a wall picture that is hanging on a nail or hook, just as it is permitted for one to erect it there to begin with. [Thus, one may remove a picture from the hook on Shabbos for the sake of showing friends or for the sake of reading it, such as by an Eishes Chayil wall picture, and then replace it back onto the hook afterwards. If, however, the picture is fastened onto the wall through screws or adhesive tape then it is forbidden to remove it from the wall on Shabbos. Furthermore, some are stringent not to remove any picture on a wall on Shabbos, even if it is merely hanging on a nail, either due to the Muktzah prohibition of destroying prohibition.]
Wall pictures which hang on hooks or nails are not considered Muktzah on Shabbos and may be moved to and from their hook on Shabbos, as desired. However, one may not erect or remove wall pictures which are fastened to the wall with screws or adhesive tape. Nonetheless, some are stringent not to move, place or remove any picture from or to a wall on Shabbos.
May the Gabaiy hang a sign reminding the congregation of Yaaleh Veyavo, or Mashiv Haruach, and the like, onto the wall of the Shul on Shabbos?
It is permitted according to all for the sign to be hung on a hook and the like.
 See SSH”K 23:39; Piskeiy Teshuvos 315:3
 See M”B 308:8; 308:168 and 501:1 that any item that is designated to a specific place and one is particular not to use it lest it become damaged, is considered Muktzah MC”K; Chazon Ish 43:17; Az Nidbaru 11:21; Beir Moshe 8:70; SSH”K 20:22 and 28:27 regarding moving a clock and picture; Piskeiy Teshuvos 308:2 [new] footnote 15 and 315:3
Background: See Admur 310:2 and M”A 310:5 that a wallet is similar to MMC”K since one is careful with it and designates for it a specific place. Accordingly, the Mishnah Berurah in 308:8 and 501:1 rules that a vessel, or wood for building, is Muktzah if it is designated to a specific place and one is particular not to use it lest it become damaged. Based on this, Shmiras Shabbos Kihilchasa ibid writes that any expensive item which one designates a specific, such as a wallet, closet, expensive picture or clock place, is MMC”K
Ruling of Chazon Ish: Seemingly, according to the ruling of Chazon Ish below who prohibits placing or removing the picture from the hook, the picture becomes Muktzah if it falls off. Nonetheless, it is possible that even accoridng to his opinion, it may be moved while on the hook, to be straightened.
 Implied ruling of Admur, brought in next footnote; See Tehila Ledavid 336:6; Toras Shabbos 308:2; Ketzos Hashulchan 121 footnote 4; Rav SZ”A in SSH”K 20 footnote 214; Igros Moshe 5:21; Yabia Omer 7:39; Piskeiy Teshuvos 308:2 [old] and footnote 22 [new]; 315:3
 See Admur 308:4 that MMCK only applies if the item is a Keli Shemilachto Liisur, unless it is merchandise in which case it is MMC”K even if it is not a Keli Shemilachto Liisur. [However, see Admur 310:12 that a money bed is similar to MMCK being that one is Makpid and designates it a specific area]; Piskeiy Teshuvos ibid learns that according to Admur 308:4 it is not Muktzah as it is not a Keli Shemilachto Liisur; However, Beir Moshe ibid states on the contrary that according to Admur 308:4 it is Muktzah as it is exactly similar to merchandise. In truth, however, merchandise is designated to be sold and is thus likened to Melachto Li’isur, while a picture is completely designated for a permitted purpose, to be looked at.
 Admur 308:15; 311:15; 276:9-10; 266:19; 301:39 KU”A 10; So also rules: Mishneh Shabbos 141a; Rosh 3:19 in name of Rabbeinu Yonah; Michaber 311:8; Michaber 308:43; Rama 308:3 regarding blowing; M”A 308:7 regarding kicking Muktzah and 308:41 regarding his question on Michaber regarding sitting on Mukztah; M”B 276:31; 308:13 and 81 and 88; 311:30; 1st opinion in Chayeh Adam; Derech Hachayim; 1st opinion in Aruch Hashulchan 311:20; Kaf Hachaim 311:68 [although brings strict opinion in 69].
Other opinions: Some Poskim limit the moving of Muktzah even with a Shinuiy. [See Ran Shabbos 20b “Kashya” and Tosafos Shabbos 43a, brought in Admur 276 Kuntrus Achron 3; Meiri, brought in M”B 308:82; Mordechai, brought in Magen Avraham ibid; Elya Raba 308:41; M”B in Shaar Hatziyon 302:35; Chazon Ish 47:12-13; Beir Moshe 1:26; See Piskeiy Teshuvos 308:20]
 See Piskeiy Teshuvos ibid; SSH”K ibid
 So rule regarding decorative sheets and the same would apply regarding to wall pictures: Admur 315:6 “It is permitted to hang decorative sheets [on one’s wall] even though that they [will be] permanently [placed there] being that they are not meant to serve as separations.”; M”A 315:2; M”B 315:7; So rule regarding curtain dividers: Admur 315:7 “Door curtains which [are sheets that are] hung in front of a doorway in substitute for a door, then even though they hang there permanently it is allowed to hang it on Shabbos , as since it moves and swings with a common breeze and also does not prevent people from walking through it, therefore it is not considered a permanent separation but rather a temporary separation and thus has no prohibition [in being made] when it is not made to remove [a prohibition]. For this reason the curtain [Paroches] which is in front of the Holy Ark is allowed to be hung there on Shabbos even if the ark does not have a door and the curtain is thus a fourth divider for the ark, as [the curtain] is a temporary separation and is only made for modesty.”; Rama 315:1; Rebbe Chiya in Shabbos 138a; Igros Moshe 5:21; SSH”K 23:39 [old] and Piskeiy Teshuvos 315:3 explicitly extends this allowance also to wall pictures
Other opinions: Some Poskim rule that it is never permitted to attach anything permanently to a roof or wall on Shabbos due to the building prohibition. [Chazon Ish 52:13, brought in Piskeiy Teshuvah 315:2] According to this opinion, it is forbidden to hang a picture on a wall, or remove a picture from a wall, on Shabbos even if it is merely hanging on a hook and is easily removed, due to the building and destroying prohibition. Thus, if the picture fell from the wall on Shabbos, it is not allowed to be replaced, and is Muktzah. [Mishnas Yosef 9:11; Orchos Rabbeinu 5:11 that the Chazon Ish prohibited people in his household from removing or placing pictures to and from the wall on Shabbos; Piskeiy Teshuvos ibid] Practically, we do not rule like this opinion. [Igros Moshe ibid; Piskeiy Teshuvos ibid] Furthermore, even according to the Chazon Ish, a picture which is loosely hanging on a nail and is commonly removed and replaced from it, may be removed and placed on Shabbos. [SSH”K 23 footnote 141 in new and footnote 123 in old]
 See M”B 315:6; Piskeiy Teshuvos 315:3
 See other opinions in previous footnotes!
 See Piskeiy Teshuvos 315:3
 See other opinions in previous footnotes!
 Piskeiy Teshuvos 315 footnote 37