This wall pattern from the Diamond/Pearl remake was originally a rendering "bug" in the original game and that they just decided to own up to and made it an intentional texture in the remake. The original game(on NDS hardware) created a Zig-Zag pattern due to precision errors while interpolating texture coordinates across the surface of the triangle. A lot of NDS emulators would incidentally introduce more rendering precision than the original hardware, and show it "correctly".