A difficult view, in more ways than one...
...but worth it. There aren't many movies that make me cry the whole way through, but this is certainly one of them.
Bjork more than plays the Selma: she embodies her, giving Selma a special grace that is as expressive and subtle as her voice. Like Bjork's singing--at times resigned, but at times overflowing with emotion--her performace slowly invades your sympathy, carrying you with her. Selma is fascinated with musicals, so the movie incorporates musical elements, including singing and dancing numbers. The sequences flow from the imagination of Selma more than the reality of her life, providing a contrast that is strikingly pathological. However, it would be hard to accept the layers of misfortune heaped upon her without escaping with her through those scenes, and you begin to cling to them--in effect you are drawn into her world.
While the pretensions of the director do show through (especially in his unnecessary and obsessive fascination with the "100 Cameras" concept that renders many of the musical scenes distant and obstructed) the power of the story rises above the technical issues, which are more than acceptable for a Cannes film. A recommended see.