At first glance, this looks like a fun-filled snap of a group of friends on a night out.
But look a little harder and it soon becomes clear that something is not quite right.
The smiling auburn-haired girl at the centre of the image appears to have an extraordinarily long right arm that stretches out across her friends, the Daily Mail reports.
The mind-bending image has left users stumped as they try to work out the real owner of the stray hand.
The picture, taken in a nightclub, has swept the internet after it was shared by the auburn-haired girl's sister, 18-year-old Eleanor Bailey from Leeds.
Posting the image on Twitter, Eleanor wrote: "My sister's arm in this club photo looks about 6ft long I'm crying."
Eleanor's sister actually has her arm around the back of her male friend, meaning her hand is out of sight.
The hand on the left-hand side of the image belongs to the brunette girl on the other side of the young man.
The unusual angle of her arm, combined with the fact that all three friends are wearing black, creates the confusing trick of the eye.