I am a H'wood screenwriter, (currently on strike and thus with plenty of time to write web commentary) and have written scripts for New Line, Paramount, Sony, etc. I know to the outsider it often seems as though the studios, in this case Disney, conspire to fill their films with all sorts of brain-washing activities designed to turn little girls into shopaholics or boys into violent warriors or whatever, but I tell you this: it's not the studios, it's the writers. It's me and my cohorts.
So why would the writers insert a shopping scene into this movie? Because it makes sense for the story. In Cinderella, when she needs to get ready for the ball, her fairy godmother appears and gives her a makeover. In Enchanted, our heroine is in the real world and needs to get ready for the ball. Is there a fairy godmother around? There is not. So how do people get ready for a ball in the real world? They shop and get a makeover. It makes sense for the story, not the other way around.
Otherwise, do you think some Disney executive was sitting around saying "We need to brainwash kids into becoming consumers. Let's but a "Pretty Woman" -type shopping scene in here at the bottom of the second act. That'll turn those little girls into voracious consumers specifically interested in purchasing Disney merchandise!" Of course they didn't. This is the real world, not some (paranoid) fantasy.