Trivia: This film has a few links to Buffy the Vampire Slayer TV program. The stoned guy with the brownies is Jessie who only appears in the first 2 episodes before getting turned into a vampire and getting killed by Xander. There is a girl who is staring at a banana - this is Amber Benson who played Willow's girlfriend Tara and finally and most obviously Seth Green who plays Kenny went on to play Willow's boyfriend Oz. See this website for more: http://www.buffyguide.com/galleries/multiple/canthardly.php.
Trivia: All four members of the band DuJour from the film "Josie & the Pussycats" appear in this film as well. Kenny, the lead singer and drummer from Loveburger, and the "love machine" foreign exchange student were the teen sensations from J&P.
Answer: The filmakers decided to forego showing Amanda's face early on to give her grand entrance at the party more impact.