It wouldn't work because all those screenshots would have to be added to game files so every player entering a house could see them. SE would be inundated with millions of screenshots that players wanted used, and complaints when someone's favorite screenshots didn't get picked for the few hundred that SE could reasonably implement.

It's an idea that could work in smaller multiplayer games where the player's local client is effectively used as the game server when players are visiting each other's "homes" but not in a massive multi-player game like this.