Mila Kunis has explained a bit more about Black Swan, her role and her preparation for the film. It’s possibly a bit spoilery so feel free to just skip this update.
My character appears and is everything that she wants to be in life. Her character is very professional, very strict and very neurotic. And, my character is very loose. The talent that my character has in ballet comes naturally to her. She’s not as technically as good as Natalie’s character, but she has more passion naturally, and that’s what Natalie’s character lacks, and so it’s a battle. It’s a yin and yang.