(at around 33 mins) When the White Bitch "shows off" her White Castle, Kal Penn's character comments, "I feel like I've been there before." This is a nod to Harold & Kumar Go to White Castle (2004), which Penn had starred in three years prior.
(at around 19 mins) In the first cut of the film, the woman who warns Lucy not to enter the wardrobe that leads to "Gnarnia" was completely naked. On the basis of that scene, the MPAA gave the film an R rating. However, the filmmakers had anticipated that the nudity might be an issue, and had filmed the scene where the actress was wearing a bikini. When they inserted that scene and the board reviewed the film again, they immediately changed its rating to PG-13.