This photo was published by Marty Mula, singer and musician. At the moment, the photo has more than 32,000 retweets and 70,000 likes - and we're not even mentioning the number of comments.
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So, neck or back?
The innocuous photo shows a young woman sitting from behind on a mattress, but with the angle of view, an optical illusion appears and plays on our nerves.
Depending on where you look, you will see either a bare back or the nape of a neck. If you focus on the hair, you will see a rather long neck. But if you focus on the bare part, you will see a naked woman.
After a long discussion, the girl in the photo broke the silence and revealed the part that is actually shown.
It's her back!
Incidentally, optical illusions are very important. They are used for neurological research to better understand how our brain works.
Caltech, the California Institute of Technology, presented a new, more serious experiment in the study of optical illusions. The photo, however, tries to make us travel in time.
