I Understand that All of the Posters are simply posters for the respected games but, I have a Theory. Each of these Posters Were Used in The Orange box on the 360. a Game or Games that Have not been Updated or At least are on a Build of the games seen in the Orange Box, I speculate that the Orange Box May be connected in some way. If the interloper can go all the way back to the Fist ever Xbox, it is possible for it to be somewhere in the Orange Box.

Again Just a Theory.