It's good to have something easily understandable, and also be prepared to be genki! Which I was not. Heh, got sick on the day of the interview so I was kinda the opposite. Anyway, I landed a job here regardless through some eikaiwa, so it's still cool.
At my interview I saw a lot of different activities. One person taught body parts using manga he drew (not a good idea), another person did a game activity where one team would change something in the room for the other team to figure out, and I did some simple preposition activity using animal drawings on the white board (ex. "The snake is next to the ___"). Good luck, and I hope you get a good placement. I've heard with AEON, it's kind of hit-or-miss, as far as experiences go.