English through movies - "Spider"

Yesterday a teenage student and I finished watching David Cronenberg's movie "Spider", which triggered an avalanche of doubts and questions about its ultimate meaning.

If you've seen it too, maybe you can help us. The student said he'd been flabbergasted by the last scene and, in all honesty, it does shed a different light on the story.

Why do you think a single actress (Ms Richardson) was cast in three different roles? I've got my point of view but I'd like to know yours.