We sincerely apologize for stoking this type of fire again, but a new version of 'the dress', 'cat on the stairs' and 'girl underwater or not' illusion has made its way online. Unsurprisingly, it's going viral.
Swiss photographer Tiziana Vergari recently posted a picture on Instagram that has several people scratching their heads in wonder. All anyone has to do is figure out how many girls there actually are in the photo.
A photo posted by tiziana vergari iPhoneography (@tizzia) on
The picture was submitted last week on March 7, as an entry for Instagram's Weekend Hashtag Project - #WHPidentity - that aimed to celebrate individuality through photos and videos.
The photo soon became very 'liked' - over 12,900 and counting - as more and more people tried to identify the exact number of girls they thought were photographed. Popular guesses among the 650 odd comments are 2, 3 and 4.
So what do you think? How many girls are actually there in the photo? Share your guesses in the comments section below.