In one, she is wearing the same black dress and hat with the white ribbon around the hat.
While playing guitar, Mary is dressed similarly to Holly while she plays guitar, albeit with a red bandana as opposed to Holly's white.
While Mary's parents are trying to marry her off, in the movie Holly was a child bride from Tulip, Texas and much like Mary Holly runs away to New York to set up a new life as a sophisticated actress in New York. Mary's father Cletus comes to get her back home, it's Holly's estranged husband in the film. Cletus in New York is wearing the same outfit as Holly's estranged husband.
In Mary's apartment is someone called H. Golightly, a reference to Holly Golightly, the protagonist of the novella Breakfast at Tiffany's, from which a film adaptation was made, starring Audrey Hepburn as the protagonist; Hepburn sang "Moon River" in the film.
The crowd shot as Bart and Homer run through the subway station is a reference to the 1950 painting The Subway by George Tooker.
9/11 is touched upon slightly. Bart tells Homer that he "would love New York, now that [his] two least favorite buildings have been obliterated". Bart then quickly adds "Old Penn Station and Shea Stadium", after a pause.
In a promo for the episode, basketball player Jeremy Lin of the New York Knicks appears dancing during the scene where Mary sings The Ballad of Cylinder Head. However, he was replaced by a New York Yankees player, probably because Lin moved to Houston Rockets before the episode aired.
Don Pardo's appearance makes him the oldest guest star the show has ever had.
While interviewing Chief Wiggum in the beginning of the episode, Kent Brockman's right eyebrow turned into the same color as his skin before it turned back to its normal color like his hair.
In the queue for the Romeo and Juliet play, many of the people standing in line appear in the line more than once.
The animation of the Simpsons in the couch gag contest notification segment is a bit off-model, one error being that in most shots, Bart's head is too tall. This could explain that this segment was rushed to be put in the season premiere.
On the close shot of Bart buzzing for Mary, her name is near the top. However, when zoomed out, he is pressing the bottom button.
At the end of Romeo and Juliet, Lisa is seen lying on the ground in costume as Juliet, but she suddenly runs to Marge's side in her usual clothes very quickly.