its not always true (hash functions are in some sense designed by brilliant people to be as hard to learn as possible) but it’s true often enough to be surprising.

if there was some score that would look at lighting etc, you probably could just tack it on to one of the loss functions somewhere and expect to see improvement.

maybe not enough to beat the system; or perhaps it would increase the lighting score but make the image obviously unrealistic in other ways we haven’t thought of.