A tweeted selfie that has gone viral on social media has shocked one man's followers.
Twitter user Andy Fuentes posted the controversial selfie picture on April 26, which shows a couple.
The image shows two young people in an embrace, facing the camera, making an apparently standard pose. But social media followers picked up on an unusual detail in the picture, reports the Daily Mail.
Take a close look at the picture and try to find out for yourself what savvy users have been able to detect. Give up? Look at the mirror in the back of the image. You might see something odd about it.
Although the woman in the picture is looking at the camera, with her back against the mirror, you can see her face shows up in the mirror anyway, which means the picture features two faces of the same woman staring back at you.
Reactions to the selfie on Twitter range from "Delete this," from one user to exclamations of "What!" from others. Some have even posted zoomed screenshots of the woman's face in the mirror to illustrate the trick.
Compounding the general perplexed reactions were GIFs showing priests waving crosses and freaked dogs barking.
One follower picked up on a clue in the picture's caption that might shed light on the matter.
"I love my girlfriend even if she's a Gemini," reads the caption below the original posted picture. A seemingly casual comment to make, some followers believe it keys people into the trick of the photo.
In the zodiac, a pair of twins represent the sign of Gemini, leading some to interpret that those governed under the sun sign are "two-faced," or having split personalities.
Some consider the caption to be a play on the illusion-trick and on the sign of the zodiac.
Other users were beside themselves, and believed the image was an accident, or maybe something more sinister.
"They are the twin sign," wrote one Twitter user. "This is a doctored photo playing off of that."
While users discussed the picture, the original poster of the controversial selfie has yet to account for the mysterious "second face" in the picture, leaving many wondering.
Other pictures shared on social media have perplexed users. In January, a girl's bathroom selfie had viewers seeing the pattern on her top change depending on what type of device they used to view it and how much the photo was zoomed.
Posted by Madeline Ochoa from California, the picture generated thousands of comments, The Telegraph reports.