interference

Two regular grids offset from each other produce a third pattern belonging to neither — the artefact is not in either layer, only in the disparity between them. This is the general case for what appears on the surface of a halted image-generation: not damage, but the visible signature of a resolution still under way, which a fully denoised output would have absorbed and smoothed off. The same reading applies to a dissolving edge, where a figure stops being a figure and becomes a distribution.