Sputnik 1 Satellite
This easter egg can be seen in all versions of the movie.
After EVE secures the plant inside her and is in sleep mode, a ship comes and picks her up to take her back to the AXIOM. In order to stay with EVE, WALL-E latches on to the outside of the ship just as it takes off.
When the ship flies through Earth’s atmosphere, it goes through clouds and then breaks through a layer of satellites. Four satellites end up getting stuck to WALL-E, one of which gets stuck to his face. The one on his face happens to be Sputnik, the first satellite in history.