Best Illusions of the Year

A little while back I posted that I was reading a very interesting book called Sleights of Mind by Stephen L. Macnik and Susana Martinez-Conde.  In the book, the authors describe an online contest to determine the best new illusions every year.  The contest is in its 7th year, and recently, the winners were announced.  Personally, I liked the "Grouping By Contrast" and the "Mask of Love" illusions the best, but then, to each his own I guess.

The Mask of Love: Do you notice anything unusual about the mask in the center?  Look closer and you may see a photograph of two faces rather than one, a man and a woman kissing.