During the scenes in the pool area and the locker room, posters can be seen in the background with the Greendale Human Being on them. However, the Human Being mascot isn't invented until the next episode.
This episode features a pay-off for a joke that was established in the first two seasons. In season one, the character Professor Slater mentions the name "Beetlejuice" while trying to recall Britta's name. In season two, Britta refers to Jeff's underwear as "stripey Beetlejuice numbers" during a conversation. And in this episode, Annie says that Britta has the "Beetlejuice" soundtrack on her computer. As Annie says the name, the character Beetlejuice is visible briefly walking by a window in the background, his name having been said three times. (In the film "Beetlejuice", he is summoned once his name is spoken three times).