The movie was really confusing, since you are seeing almost all the scenes from the point of view of Nina, who is going quietly mad in her quest to perform both parts perfectly. Several scenes that you think are real end up being hallucinations, and the director, Darren Aronofsky, doesn't help you separate the real from the imagined. In fact, by the end of the movie, I am not at all sure what actually happened, other than that she gave a performance that riveted the audience. I found this excerpt from a review by Chuck Koplinski (he reviews three movies; the second one is Black Swan):
I’m not sure all of the narrative pieces fit together, but that’s Aronofsky’s point. An examination of one’s descent into madness is only effective if we are put into the shoes of the afflicted, and the film does just that. Thanks to the filmmaker’s audacity and a fearless performance from Portman, Black Swan proves to be a gripping, shocking and haunting look at the fragility of the human mind and how defenseless we all can become to our fears and insecurities.It's not a movie for the faint of heart, but I am glad I saw it. I cannot put Portman's Black Swan out of my mind and keep seeing her face, thinking that if anybody ever deserved an Oscar for a performance, it's Natalie Portman for this one. It was breathtaking.