This takes place before the curse was broken. Swanqueen!
Emma gives Regina an apple as a gift as she has secret feelings for her.
Regina wonders why Emma would give her an apple. Regina remembers that in ancient Greece giving an apple to someone was a marriage proposal. Regina thinks Emma is playing a game with her, trying to one up her. So Regina, wanting to win, accepts Emma's marriage proposal.
Henry looks through his book to see if he can figure out why his mother is so interested in the apple Emma gave her. He finds out what it means and becomes excited.
And Emma has no idea what the hell she has done and how to fix it, does she even want to fix it?