This photo of a 'three-legged woman' has the internet stumped

Another optical illusion has taken the internet by storm. This may join the ranks of the dress and the woman with a "missing" leg. This one involves the opposite: a woman with supposedly too many legs.

The photo popped up on the image sharing site Imgur:

The photo has gone viral because she appears to have three legs. She does not, in fact.

Check out these other optical illusions

Can't figure it out? She is holding a vase!