tbh I thought this was a commonly used technique even prior to LLMs? I know I've been using it extensively myself, but I was inspired by Dolphin's extensive visual CI system.
I do that on my renderer. each commit when it's ready to be merged gets a class of visual diffs. Dolphin's way was a major inspiration how to structure it, but it was _the way_ in rendering way before it.
If it is common in the world of video game porting, that just shows my ignorance. I'm familiar with visual diffs in CI for e.g. web development (comparing a static component), but to do that to compare frames over time in a video game/3D environment is new to me.
There are so many more degrees of freedom, which I can see Claude handled... mipmaps, subtle differences in lighting/positioning/compositing etc.