Ah! The Diorama Efect!

It must be because of the way the ground and the objects at back of table are blurred. The objects also have this.... flatness to them, or maybe they've been slightly squashed by the tilt... Anyway, very interesting!

Nice photo too! I often call myself an anti-cat, when I see cups near edges like this I automatically push them back onto the table farther so they won't spill!