This marks the first time (if not the only time) in the series that Trent refers to his sister as Jane rather than "Janey", his preferred name for her.
Although the store Cashman's is mentioned numerous times throughout the series, mainly by members of the Fashion Club, this is the first time in which it actually appears.
Daria's exclamation "Marcia, Marcia, Marcia" to Quinn's nonstop chattering about her dates is the phrase used by Jan Brady ("The Brady Bunch") when speaking to her older sister, usually when whining about some perceived unfairness or another.
While Trent and Daria are looking for a present for Jane, Trent shows a dress to Daria and says that she'd look cool in it. The same dress is shown on Daria in the credits of season 1 episode 1.
When walking down the street looking at shops, Trent says Daria would look good in an outfit that is a checker pattern top with an orange skirt. Daria actually previously wore this outfit in Season One's "Alter Egos" that play over the end credits.