You’re probably thinking, “What’s the big deal? It’s not like the spiral is spinning. It’s not 3-D. I don’t see Mother Teresa’s face jumping out at me.” True. But there’s something you might not realize. See the blue spiral? And the green one? THEY’RE THE SAME COLOR.
Go ahead, take a look.
Still don’t believe me? Check out this post over at Discover Magazine, which explains how the mind interprets colors based on surrounding hues. Then grab a Kleenex and wipe your brain off the walls.