Fooled by depth
Accidental viewpoint
A painting of a man on a flight of steps. What happens if you take a step sideways?
It falls apart into stripes.
Why? Your brain assumes you aren’t standing in a special spot where things just happen to line up. Artists put you exactly in that spot.
Picture: Sivi Steys, CC BY-SA 2.0 · Wikipedia(opens in a new tab)