The song used twice in the episode, particularly when the text on the screen towards the end is telling the viewer what has happened to the characters after the episode, is "Creep" by Radiohead covered by Scala and Kolacny Brothers," which was also used in the trailer of The Social Network.
The episode was too short so "A Simpsons 'Show's Too Short' Story" was placed at the end. This was animated in a similar way to the Dark Stanley story from "Yokel Chords," with similar music playing.
The story pays homage to Tim Burton's 1982 stop-motion short film "Vincent", which was about a young boy who imagined he was horror movie icon Vincent Price. The poetic narration of the short was modeled on the same style employed by Tim Burton.
The artwork of the "Show's Too Short" story pays homage to Edward Gorey, an author and illustrator known for his dark humor and also for his animated opening to the PBS series Mystery!.
Lisa somehow knows what her family did when they went to the mall, even though she was not with them. She even says that she has left certain parts out. They could have talked about what they did in the shopping later that day, as that was a flashback.