Thanks Jeff - good example. Also someone on the main board pointed out a case where there was an issue (Philadelphia I think) where a bunch of players were pictured in front of Jim Brown's cadillac.
It reminded me that in video games, they used to call these "Easter Eggs" - when the developer added a secret message or secret room or something that wasn't documented. Also
The Da Vinci Code novel, but I think some of the stuff he saw in the paintings was a bit of a stretch