The sky
The imagery of the sky is an important factor in the movie. All throughout the movie, the sky is gray, providing a grim and depressing atmosphere. The movie ends with a shot of blue sky indicating that Sadie is finally free of the burden pinning her down, she is free from the abuse and is able to move forward.
Music
Music plays a large part in the movie. Sadie uses music as a means to direct her anger and motivate herself and abuse victims to free themselves from the abuse. The aggressive music used as a positive motivator is in direct contrast with the slow love song that triggers Sadie's panic attack and brings her down enhanced with her husband later on humming the same song while she's tied up in his cottage.
Final revenge
As a final act to humiliate the abuser and her son's killer, to enact revenge, Sadie leaves his naked body out in the snow to be found. It portrays her regaining control over herself and her life: he can no longer control her, the revenge is complete, and she is free.
