Unrelated to anything else: It's not a "real" ballet movie until you see the gnarly-feet-and-how-I-customize-my-pointe-shoes montage. If I had time, I would make a montage of these montages. Perhaps at the Oscars?
Portman plays the sh** out of Nina. I have never felt so anxious in a movie theater. Nina has two things in her life - ballet, and her mother (in that order). That's it. She doesn't have any other friends or family or any other hobbies or interests. Get up, go to the studio, dance dance get yelled at dance dance, go home, get doted on, go to sleep, repeat.
Nina appears to be a woman, but Portman certainly does a good job making her a lost girl. She speaks with a higher pitched, more girlish voice. She lives in a pretty pink bedroom. (OK, that's not really Portman's doing, but it clearly screams "not yet a woman.") She lives to please others, and to succeed. At ballet. That's it. Her mother was a dancer, but gave it all up to have Nina. So, you know, no pressure on her or anything. None at all...
At the beginning of the movie, the premier soloist at Nina's ballet company is forced into retirement. (Winona Rider does a good job playing this bitter, rejected role, although you wonder how much of it is acting.) And the ego-driven artistic director wants to do a season of "re-imagined classics." (Re-imagined by him, of course.) Starting with Swan Lake, which, I'm paraphrasing, but "has been done to death ... but not like THIS," according to him.
I'll admit, I've never seen Swan Lake, so I didn't know the story of Swan Lake going in. It goes something like this: pure, virginal white swan falls in love, gets cursed, turns into seductive black swan, her love picks another girl, she kills herself. (Perhaps she is friends with The Little Mermaid. The real one, not the Disney one.)
Whoever is cast as the Swan Queen has to be able to dance both the white and the black swan - the Madonna and the Whore. (How original.) Nina has the technique to dance the white swan perfectly, but she does not have the passion to dance the black swan. (Probably because she was forced into ballet by her mother and then beaten down by an overbearing artistic director ... just a hunch ... and probably because she was never allowed by her mother to have any real joy in her life, just ballet ballet and more ballet.)
Enter Lily, who conveniently has come to fill in at the company from San Francisco. Lily is everything Nina is not - imperfect technique, but she has all the passion and seduction. She eats and drinks and smokes and parties and sleeps with boys. Nina has all the technique but lacks passion and seduction and barely eats, never drinks, doesn't smoke (although she tries to fake it), doesn't party and we're pretty certain she is a virgin despite her claim otherwise. Lily is outgoing and confident and sexy and Nina is uptight and insecure. Like most women in movies, you are either the Madonna or the Whore.
And she becomes the black swan. Meaning she's perfect.
But what next? Where do you go from there? See it and find out.