A picture is worth a thousand... arms? People are losing their minds over this latest illusion.

By Blake Bakkila
Updated May 03, 2017
Elle Bailey/Twitter

Meet the latest viral optical illusion: a 6-foot-long arm.

On Monday, a U.K. teen shared a group photo that has since gone viral because of a mind-bending optical illusion. In the photo, it appears as though one woman has an extremely long right arm.

“My sister’s arm in this club photo looks about 6ft long I’m crying,” 18-year-old Eleanor Bailey shared on Monday. All three individuals in the top row of the photo are in black, so it almost looks like the young woman’s arm extends to the left side of the photo. In fact, it’s her friend’s black T-shirt matching her other friend’s bent right arm. Most of the confusion was directed toward how the woman on the left angled her right arm, making it look like the hand belonged to Bailey’s 23-year-old sister Tab.

Bailey tells Real Simple she had no idea the photo would have such an impact on the Twitterverse. “It’s been very strange!” she says. “We weren’t expecting it at all. It’s very funny, though. [I’m] glad so many people have found it so amusing.”

One person even shared a detailed explanation using markers to indicate which limb belonged to each individual. But facts didn’t stop people from losing their minds over this photo. By Wednesday, it had accrued over 15,000 likes and more than 3,700 retweets.

“I can’t trace who owns the hand,” one Twitter user wrote. Meanwhile, others shared popular gifs explaining their confusion and reactions, and there was even a suggestion that the long-armed girl join the Fantastic Four.

“I would definitely not want to face her in a ski ball competition,” a Twitter user joked about the illusion.

But some said they knew what was going on all along.

“Easy to see just a perfect alignment on the shirts,” one person tweeted on Tuesday. Though reactions varied, the tweet’s online popularity prompted Twitter to feature the image in its “Weird” section as “The curious case of the girl with the 6-foot arm” on Tuesday.