When selecting the juke box for the show, Artie wants to go with the Zodiac so as not to be cliche. However, he later scoffs at Finn's proposal of a Sandy that isn't blonde (Marley) and a transgender Rizzo (Unique) because it isn't the norm.
While Blaine is sitting in the choir room singing "Hopelessly Devoted" and flipping through a scrapbook, a page with a candid photo of Kurt and another bicycle item on one page is shown both before and after Blaine flips the page.
The sign on the wall behind Mike and Tina when he's imploring her to audition for Grease says "PEP RALLEY." (spelling error)
Finn tells Ryder that he graduated with a B+ average, but recently told Rachel he "barely graduated high school."