The "song of the old country" the cats are singing at the table is actually "Look down" from Les Miserables.
The two men in line while Bojack and Diane are waiting for public records are wearing Todd Fashion.
One of the posters in the background is a parody of the Bojack Horseman Season 2 teaser poster
At 13:29- poster in Albino Rhino Gyno's office is titled "Girl Parts".
One of the posters in Princess Carolyn's apartment is an actual recreation from the movie "Junior" starring Arnold Schwarzenegger & Danny Devito thats about a man trying to conceive a child. The poster had been shown in previous seasons as one of the few, (if only) "non-animal pun" movie posters in the background. The theme of the entire episode is Princess Carolyn & Ralph trying to conceive a child.( Told through the perspective of her future granddaughter, giving an oral report in history class) In this episode however, the characters in the poster feature Heath Ledger's "The Joker" smiles drawn on their faces ( in likeness of "The Dark Knight"'s 2008 movie campaign posters.) as both a tongue-in-cheek gag alluding to the episode's premise & outcome, as well as nods to the connections of Arnold & Devito's roles in previous Batman films.