The strangest things sometimes take off like wildfire on social media; how else can you explain the furore over the colour of a dress for example?
In keeping with the online tradition, people all over the web are currently losing their minds trying to correctly figure out the number of girls in an image published on Instagram by Swiss photographer Tiziana Vergari.
The image has been shared more than 12,900 times since Vergari posted it on her page a week back.
So, how many girls are there in the picture? Hundreds of comments poured in as people debated whether there are two, four, five or even 13 girls in the picture.
"There's two. They just have a mirror on either side of them. It shouldn't be that complicated. I don't know how people aren't getting the concept. If you have a mirror in front and behind you, you're going to see the back of your head in the reflection of the front mirror. Doesn't mean there's two of you," an Instagrammer wrote.
"There's clearly four. Look at how the reflections are. If you see their face, the mirror shows the back of their head. If you see the back of the head, the mirror shows the face. The girls just look similar," another user said.
While that might have confused Veragari herself, here's a user who could see three girls out there. Why three? "Because if it were just the 2 in the middle. Then how does that explain the reflection being taller? there are three girls there." Genius, isn't it?
And this guy almost won the debate with an epic finding. "12, if you answered the question correctly. It asked how many girls? NOT how many different girls," he commented.
Although Veragiri has confirmed that it's just two girls, the debate is still raging on social media. Two, three or four, what would be your answer?