She and -her- friend went to Holt Renfrew (A canadian Luxury department store, like Saks or something) to buy her friend a prom dress. Her friend's parents are both doctors, and are very wealthy. They shop at Holt's -all- the time, and her friend often wears expensive clothing.
People will often enter the mall through the Holt's entrance, just cutting through as a shortcut. The two girls come through the doors, and her friend starts heading for the dress section, towards the front. She pauses to look at a Vuitton wallet, and a sales girl leans over the counter and says "Um...urban behaviour [a cheap clothing brand] is -that- way."