The goal is to unveil all 6 pairs of photos using the smalled number of guesses. 6 is the minimum score, if you are very lucky.
There are four groups of photos: equestrian statues, neon signs, scenes of Washington, D.C., and the Washington Metro. Each new game will use a new theme.
Use the game to discover photos on Flickr. Describe which photos to look for (blank fields match all):
To read more about this game, see JavaScript Concentration Game and Game-ifying Flickr via Concentration. You might also enjoy playing Mastermind and Hangman.