Here's a classic visual illusion of a dalmatian dog in a sun-dappled field, but really, all you see are black dots against a white background. Our brain makes sense out of this black and white stimuli, and "sees" the dog.
This summer I was hiking and suddenly, from the underbrush, in romped the dog seen in the second photo. He posed briefly, then dashed off to join his walking companion.
And thus does life mimic art.