If you've been on Twitter recently, you've probably seen this optical illusion knocking about.
Basically, for most people, it will look as though the image is moving, even though the illustration is actually perfectly still. Spooky.
But according to tweets (and one now-deleted Tumblr post), it's not just any old illusion. The posts claim the speed at which the image moves shows you how stressed you are.
“This still image was created by Yamamoto, a Japanese neurology professor, and he told the instructions below,” the original post reads. “If it’s not moving, or just moving a little, you are healthy and have slept well. If it’s moving slowly, you are a bit stressed or tired. If it’s moving continuously, you are over-stressed and might have mental problems.”
But here's the thing: that's all fake. The image was really created by Yurii Perepadia, a 50-year-old designer from Oleksandriya in Ukraine. He drew it in 2016 and it took him about two hours to complete. And most importantly, he says the image has nothing to do with how stressed you're feeling.
"I first saw this fake post on Facebook and then they began to appear everywhere," Yurii tells BBC Three.
"It annoyed me. After all, it was copyright infringement. So I wrote letters demanding the removal of the posts."
But despite Yurii trying his best to get the posts taken down, people on Twitter continued to share the illusion...
And drew conclusions about their health (albeit in a tongue-in-cheek way).
So Yurii decided to take matters into his own hands, by posting about it on his Instagram.
“I drew this optical illusion in Adobe Illustrator on September 26, 2016,” he writes. “To create it, I used the effect of Akiyoshi Kitaoka. This is a white and black stroke on a coloured background… which sets in motion the focus of vision and it seems to a person that the details of the image are moving.”
If the name Akiyoshi Kitaoka rings a bell, you might remember this incredible - if somewhat infuriating - illusion with 12 dots on a grid.
Since posting about his graphic on social media, Yurii says he's happy people have now realised the claims are fake.
"When people found out I was the author of this picture, it helped me bring out the truth," he says.
In any case, an optical illusion is not the best way to tell if you're stressed. If you are at all worried about your mental health, then it's better to see a qualified professional than to try to self-diagnose from Twitter.