I would call this "optical illusion", just to get people to stare at it looking for the illusion.
[LIDIYA A & MIRANDA A at Met Art.](http://hosted.met-art.com/Full_met-art_sg_444_693/)
Suddenly I'm hungry to eat at Wendy's
this got me to audibly say "oh myyyy"
Suddenly I'm hungry to eat at Wendy's
this got me to audibly say "oh myyyy"