James Mangold is a storyteller that digs deep into his characters in order to reveal their emotional states. And the point of it is to drive the story forward rather than be a catharsis. We watch as Susanna journeys from a state of being completely wrapped up in her mind into one of freedom. Mangold shows this clearly when Susanna is in a therapy session and she zones out into a memory. When Mangold cuts back to Susanna in the present time her cigarette is nearly half burned down. Without any character having to say a word we understand just how long she has been away and where the issues lie, within her mind.
Mangold also revealed on the DVD commentary that he studied The Wizard of Oz in order to prepare for this film. He looked at Susanna's journey as one where she was going into a world she knew nothing about in order to understand that who she was on the outside was something very real and she is given the tools and perspective necessary to move forward with her life by being in the mental institution just as Dorothy learned by being in Oz.
One camera move that Mangold used to relate Susanna's entrance into the mental institute to Dorothy entering Oz is a tilted perspective as she enters the hallway where she will live for the first time. The tilt happens suddenly and reveals that she is completely off balance in this new environment. It makes us feel as she does which is scared, a little sick to our stomachs and understand that this is an unpredictable environment. Mangold goes on to use a simple and straight-forward technique to reveal someone's journey from getting out of their mental memory prison and moving into a place of authority in their life.
