I Am Sure We Have All Seen,

one of the many optical illusions that can look like two different objects,

 depending on how we focus our eyes on them, well here are a few that I came across that are upside down illusions, like the one above, from a deer to a seal,

 or from a ponderous elephant,

to a graceful swan, they are a fun ad campaign for Jeep from Leo Burnett Paris, what a neat way of looking at things and getting notice and not a single picture of the product!