Michael tells Erin that Angela is old enough to be her mom. In reality, Angela Kinsey is only 9 years older than Ellie Kemper.
According to the podcast "The Office Ladies", the actors who tried out for the waiter part looked "too Hollywood" to play a Scranton waiter and the show could not decide on an actor for the part. After a writer on the show, Aaron Shure, walked across the room to go to the bathroom, he was selected.
When Michael approaches Erin's desk to ask her to lunch, Erin is wearing purple flower earrings. According to the "Office Ladies" podcast, they are the same earrings that were worn by Pam in Weight Loss (2008).