“I saw a large print of what was presumably a medium/large format Martin Parr photo at an exhibition in which one of the people’s faces looked almost 3D. I’ve seen a similar effect with a few other medium/large format exhibition photos.
Obviously the prints are extremely detailed but why would that make them look 3D?
Quite apart from the 3D effect, some of these pictures look more real than reality, in a way I can’t put my finger on. Does anyone know why?
There must be some good perceptual psychology stuff on this somewhere!”

Why do large format photos look 3D and hyper-real? – Photo.net Casual Photo Conversations Forum