The texture of a wall in a Stinky and Loof in Wonderland custom style is defined by a wall atlas. This is a 768x1024 image that is a grid of twelve 256x256 subimages. Six of these (the ones colored in the diagram to the left) comprise a cross that can be wrapped around a cube to form the wall. The other six (the ones in white) are ignored by the game.
The six wall subimages are all oriented so that their top is to the right.