a picture that appears to be an ordinary picture but, when meticulously examined, contains a sketchy character (i.e.: a ski-masked ball-scrather) making an unusual face in the background (i.e.: accentuation of double, triple, etc. chins; creepy stares)
Joe: "Look at this picture of me with Obama that I took in DC!"
Joe: "No, look at that guy in the back!"
Anthony: Looks more carefully "HOLY SHIT! AN UTZ PICTURE! THIS IS AMAZING!"