In just a few moments, a person who has never once lost an argument is about to be completely undone by a photograph. They will look at it with the relaxed confidence of someone who considers themselves sharp, observant, and generally ahead of the curve, but that feeling won't last. This is what puzzles do to people, and this is exactly why we love them.
The human brain is a spectacular piece of machinery that is also, under the right circumstances, catastrophically easy to fool. A cleverly hidden object, a manipulated image, a pattern that refuses to resolve itself no matter how hard you stare, and suddenly the most intelligent person in the room is leaning three inches from their screen, muttering to themselves.