A painting that, when put on a wall and left alone, during an undisclosed time period will change the wall in the painting with the wall it is on.
I was thinking of adding a picture of a painting with a man on a chair in front of a wall that has been switched into the painting but it is hard to find one that looks out of place.
Also I thought of adding a picture of a wall that has been switched (miscalculated or poorly made buildings that have stuff that seems out of place).
Ideas of what might happen:
1. The painting is put on a cell wall inside the Foundation and after a while it changes the solid wall into a wall with a door that leads to the next cell causing the SCP in the next cell to move to it's cell and the painting to have the previous wall on it.
2. During testing the painting is hung into the middle of a cell and after a while it is discovered that the painting has created a wall behind it and inside the painting the wall is just further away.
3. When hung outside the painting creates a wall the size of the wall that it was previously hung onto (depending of the size of the room it was in). It is discovered that the painting can only manipulate the wall behind it and will just erase the wall if it wasn't previously hung on a wall causing it to create the strings or whatever it was hung up by to go into the ceiling and have it hung by them.
4. If the painting isn't able to stay at it's location on the wall and fall to the ground it will change the floor inside the painting with the floor it is on. Same happens to the ceiling.