optical illusion

A Provincetown man accidentally captured a seagull in flight that looks strikingly like a mountain in the background, creating a once-in-a-lifetime optical illusion.

Whoa!

No this girl's arm is NOT six feet long. It's an optical illusion caused by the perfect positioning of people, their clothes, and a furry coat. 

This optical illusion took me an embarrassingly long time to figure out, even after it was pointed out to me.