In the scene during which Joel is eating Chinese food and watching TV on the couch with Clem, the TV starts showing some interesting things. First, as Joel gets up to investigate the voices of Patrick and Stan, we see the TV reflecting Clem, who's still sitting on the couch eating her food. Then Joel walks behind the TV, and instead of acting like a mirror, it behaves as if it's a window. We can see part Joel's torso and the box of food he's holding on the TV.
This is a cute visual trick that's hard to notice at first. There may not be any specific importance attached to it, but Gondry has used similar imagery, what you could call mise en abyme, or pictures within pictures, in many of his other works, including music videos. Maybe he's drawing attention to the fact that Joel's life is like a television show to the Lacuna employees, who are basically mapping out the past two years of his life. Maybe it's about how, in a way, Joel is watching himself, and we as an audience are watching Joel watching Joel.
As an additional little fun fact, one of the programs on Joel's TV is the unaired pilot episode of the 1960s TV show The Munsters, called "My Fair Munster." The scene playing from the episode features the grandfather character trying to find the recipe for a love potion—which is something that Joel could probably use. Also, remember that it's Halloween, so it makes sense that this would be on TV—but it's funny that this is the unaired pilot, a lacuna in the history of the show.