One of the ways that Alisha entertains Roscoe (and that Roscoe entertains himself) is by putting a mirror into his crib. It must be strange to him to occasionally see a circle drop down with another baby inside of it. He doesn't yet know that the baby he's looking at is himself.
What kind of conversation would you have with yourself, if you didn't know it was you? Would you correct your own mistakes? Would you point out something in your teeth? Would you cordially greet yourself and then try to find your way out of the situation?