Fluttershy's neck disappears after she says, "I don't know if I can cheer enough to help her".
There are a lot of Greek references. Cerberus, Tartarus, a messengers boots (Hermes reference) and the princesses. Twilight is the Greek word for friend love, or Philia. Cadence is Eros, or romantic love. Celestia is Agape, the love God has for mankind. Well, Celestia is kind of a god. Luna is Storge, love of a mother and child. This works because she has helped Scootaloo and Sweetie Belle in a motherly way. She was a mentor to both of them.