The dark-haired young girl in the Lillypads classroom wearing the pink, flowered dress who holds up the head of the anatomical model and screams, is Max Greenfield's real-life daughter, Lilly.
Nick says to the woman who punches him in the face "it was always you," which is a phrase the hook in the song "I Always Knew", which played at the end of season 2, signifying Nick and Jess' romantic tension finally turning into a relationship.