Jacqueline tells Titus that if he drops out of his movie he'll have to go back to making "stupid karaoke videos." In a previous scene, when Lillian (or Cyndee) is singing, if you look at the karaoke video in the background, you can see that Titus is in the video.
Ellie Kemper was pregnant with her second child during filming, and her clothing had to be adjusted in a way that would hide her belly.
Jack McBrayer plays a character called Sandy Parcell. He had previously played Kenneth Parcell on 30 Rock (2006), another show written and created by Tina Fey. It is unclear if these characters are intended to be related.
The director of Titus' movie, the director (character name Shawn) is played by the same actor who plays a director of the same name in 30 Rock. Tina Fey has previously stated that both 30 Rock and Unbreakable happen in the same universe, so it's likely it's the same character (just like Alfonzo the piano player).
Depending on the decisions taken, Friederick's middle name may be either Eurythmics or Bono.