This incredible picture taken by Tiziana Vergari, a famous Swiss photographer, went viral after it was posted on Instagram. The breathtaking picture shows several girls sitting near mirrors. That's where the magic happened. The mirrors created an optical illusion, which makes it difficult to tell exactly how many girls are in the picture. View this post on Instagram Same but different | My entry #whpidentity for @instagram [thank you #instagram for this featuring ❤️] A post shared by tiziana vergari (@tizzia) on Mar 6, 2016 at 1:47pm PST A helluva brain teaser!This enigmatic photo has been shared several thousand times on social networks. The photo was liked and shared more than 14,400 times. A lot of users posted comments under the posts, sharing their guesses of the exact number of little girls in the photo. Some say there are two, others see fourteen. While one user wrote: 4 girls, 2 sets of twinsanother suspected: There are clearly four of them. Look at the reflections. If you look at their faces, the mirror shows you the back of their heads. If you look at the back of their heads, the mirror shows you their faces. The girls just look alike.So, what's your guess? This picture will probably have you banging your head against the wall, it's the perfect mental exercise!Check out the video!