It turns out that Nina hallucinated the fight with (and subsequent murder of) Lily, and actually stabbed herself while in the throes of a psychotic episode.
In the final ballet performance in Black Swan, Nina is flawless and seems to have achieved the perfection that she was striving for so long. But given that her abdomen wound was still open and bleeding, she most likely succumbed to the bleeding as she falls through the air and lands on the mattress.
There are simply too many psychological issues going on with Nina. She shows elements of an anxiety disorder with obsessive compulsive behaviors. She also manifests self-injurious behavior and some signs of an eating disorder.
Summaries. Nina is a talented but unstable ballerina on the verge of stardom. Pushed to the breaking point by her artistic director and a seductive rival, Nina's grip on reality slips, plunging her into a waking nightmare.
NOT REAL: Therefore, Lilly and Nina did not have actual sex (we know this because after sex, Lilly said something to Nina about being a ‘Good girl’ and then tried to smother her. Not real!)
But speaking as a psychiatrist, Lamberti said the film did not accurately depict schizophrenia, as has been widely speculated, but "does present a reasonable portrait of psychosis." "People tend to be scared of things they don't understand," he said.
Similar to most real-life presentations, Nina's psychotic symptoms gradually worsen over time. Nina's disturbance in perception is evidenced by hallucinations, which evolve from shadows and seeing her face on others, to Nina's belief that she is physically transforming into a swan.
Taking a solitary walk by the lake, the young Princess Odette encounters the wicked Von Rothbart. Overcome with fear, she turns and runs in the hope of escaping his evil power. However, she is not quick enough, and Von Rothbart casts a spell on Odette, transforming her into a swan.
Thomas notes that Nina clearly came with the intention to change his mind, to try and seduce him, in the mildest sense of the word. Thomas wants Nina to lose herself, that is how she can become the Black Swan. Thomas forcefully kisses Nina and she bits him.
The night before she is set to perform, Nina becomes convinced that Lily is going to take her place. Her paranoia and mental strain cause her to hallucinate that she's physically turning into the role of Odile, the Black Swan, complete with red eyes and black feathers protruding from bird-like skin.
Even with Thomas Leroy's (Vincent Cassell) twisted take on "Swan Lake" in Black Swan, the same basic story is told, with Nina tasked to play the white swan and the seductive black swan. As a result, Nina performs the closing number with a stab wound in her chest, which results in her actually dying at the end.
Destruction of the body is the basis of all horror, but Black Swan's body horror serves a dual purpose by not only freaking out the viewer but also using symbolism to represent the decline of Nina's mental state. Though it isn't as overt as most other horror films, Black Swan is no less terrifying.
Lily was the evil twin and the director of the play was the prince, Lily was seducing the director (Thomas) but Nina becomes the black swan and seduces him but ended up killing herself to finally free herself from the constant burden she puts on herself to be perfect all the time.
It is, though, far from being the whole truth. The “Black Swan” screenplay has surely been prompted by a number of dancers' memoirs — Gelsey Kirkland's 1986 best seller, “Dancing on My Grave,” is just the most famous — to convey its neurotic version of the internal life of ballet.
Because the character of Odile is actually the evil Von Rothbart's daughter magically disguised as Odette, the two roles are most often portrayed by the same dancer, but occasionally they are danced by two different dancers in the same performance.
Previously, Baron Von Rothbart transformed Princess Odette into a swan, which is the symbol of beauty and purity. Because she refused his hand in marriage, he bewitched her so that she could not marry another. Von Rothbart's expectation was that in captivity, she would eventually consent to marry him.
But what you're looking for isn't how similar the dancing is, but rather how different. Where Odette was soft, Odile is sharp. Where Odette was innocent, Odile is seductive. This role is the ultimate test of a ballerina because she has to be able to do both kinds of dancing with equal skill.
The two fight, breaking a mirror. Nina stabs her doppelgänger with a large shard of glass from the mirror, killing her. The body reverts to Lily. Nina hides the corpse in the bathroom and takes the stage, dancing flawlessly as Odile and seemingly turns into a black swan, her arms covered in feathers.
In particular, Nina's relationship with Erica feels incredibly abusive and restrictive. As the film progresses, the foundations of this precarious mother-daughter bond begin to crumble precipitously.
Nina is a teenaged girl, and she is being sexually abused by Thomas and her mother. The world of professional ballet looks nothing like what we see in the movie because it isn't one: it's a ballet school, Thomas is an instructor, and the Swan Queen production is a one-night performance by students.
Following another hallucination of seeing her face imposed on someone (Beth), Nina winds up outside of the hospital holding a bloody nail file, which is what Beth used to stab herself with.
