This regular photo of three friends has the internet going crazy. Can you figure out why?

Optical illusions are intriguing works of art that play tricks on the eye. Whether you’re seeing something that’s not truly there, watching a still image move around, or finding different shapes and messages in a single image, there’s something incredible about these illusions that keep us simultaneously entertained and mind-boggled.

Also referred to as “visual illusions,” these images come in many forms. Sometimes, they even appear when you least expect them to in what otherwise seems to be an average photo.

While some illusions are a product of careful photo editing, some of them are unbelievably real. It’s all about snapping a photo at just the right moment! In fact, the simplest, most unexpected optical illusions can often be the most enjoyable ones to discover! They leave you with tons of questions because you can’t always figure out how what you’re seeing is possible. The inability to understand them is what makes them so totally fascinating.

You might be wondering how these illusions are processed in our brains and why they’re so tricky to comprehend. Your perception of the optical illusion you’re looking at is different from what exists in reality. Your eyes send a message to your brain when you take a look at something. When your perception doesn’t match up with your brain’s measurement of the illusion’s source, you grow confused because the stimulus just doesn’t seem to make any sense. Physiological illusions, like the one in the video below, are a result of excessive stimulation due to things like brightness, size, tilt, position, movement, and color.

You might not notice the following illusion right away, but keep watching! You’ll be blown away when you figure out what makes these friends’ photo so unique. Were you able to spot it immediately? Let us know in the comment section! Then, share this video with your friends to see if they can figure it out!