In an earlier episode, Naomi shows up to school in sweats and UGG boots while Annie says, "Is she wearing UGG boots? What is it? 2002?" In the same season a few episodes later, Annie is seen sitting on her couch at home wearing gold UGG boots herself.
The first season focused on paying tribute to the original series, however, after the first season barely got picked up for another season, the show got new producers who changed the entire direction of the show, and lots of elements of the original series were dropped.
The house bought by Naomi and then by her sister, Jen, is the same house Nolan Ross bought on TV series Revenge (2011). Both shows take place across the country from each other, but both are at locations with a beach near by Revenge (2011) is set in the Hamptons, which is on the east coast; 90210 (2008) is set in Beverly Hills, which is on the west coast.
AnnaLynne McCord's character, Naomi Clark, had her boyfriend cheat on her after prom in the first season. McCord also had a brief role on The O.C. (2003) as a prom goer who is caught with Marissa's boyfriend cheating on her.
Upon its first season, 90210 (2008) was heavily criticized for its three leading actresses being considerably thin and underweight (considering their height). Jessica Stroup, at 5'8," weighed a mere 100 lbs, approximately; Shenae Grimes-Beech, at 5'3," weighed approximately 90 lbs; AnnaLynne McCord, at 5'7," weighed approximately 110 lbs.
The trivia item below may give away important plot points.
At the end of Season 3, Annie was planning on attending Carnegie Mellon University, Liam was going to go to Drexel University, and they were going to live together. While both schools are in Pennsylvania, Drexel is in Philadelphia and Carnegie Mellon is in Pittsburgh, which is roughly a five-hour drive from each other.