It occurs to me that noticing difference is one of the things our brains seem to do best.

Well, speaking for my own brain anyway... other people's brains may vary

Seeing certain discrepancies seems to interfere irreparably with the all important ability to suspend disbelief (when looking at any image, whether it's tooned, realist or even a photograph).

But not seeing any discrepancies, indeed not seeing some quite large differences, in places, can have the exact same effect!