1. In the subway scene in the beginning of the movie if you freeze frame you will see Nina is seeing herself and not Lily, although later on in the movie Lily is wearing exactly the same clothes and earrings.
2. In the underground passage scene if you watch the scene frame by frame you will notice that the girl approaching Nina is Lily...
3. ...only to change into Nina just as she passes her.
4. The club scene: Rothbart and Nina as White Swan are seen.
5. The club scene: Beth is seen between Nina and Lily.
6+7: The club scene: Thomas appears behind Nina, in the next frame he changes into Rothbart.
8,9, 10: The bizarre rash appears in various moments in the movie.
11+12: The ballerinas Nina sees during opening night all have her face. One of them even winks at her.
13+14: The club scene: Nina as Black Swan is seen in two frames.
15+16: The club scene: Black Swan's eyes
17+18: In the scene when Nina is crying in the studio and the dark figure appears when she is standing in the shadow she is Nina, but after she says "Hey" and steps closer it is Lily.
19: Thomas has skeleton Swan in his office.
20+21: In the scene where Nina trips during showing Thomas her Coda there are 4 turns - during first two we see Thomas screaming "attack it" during 3rd we see Nina looking with a smile in the door at Nina failing to dance perfectly and during 4th we see Lily in the exact same clothes entering the room.
22: The club scene: Nina in partial Black Swan make up.
23: The club scene: Butterfly wallpaper from Nina's bedroom is seen in the background.
24, 25, 26: The club scene: When Nina is looking for Lily several images happen - Nina in Black Swan make up and Nina multiplying, almost as if she was in kaleidoscope.
27+28: When Nina is late to her rehearsal after the night in the club and when she is walking to speak to Lily about her telling Thomas Nina was crying she is seen scratching her back.
29+30: When Nina is looking for her mother the face on the green painting changes - the eyes are following Nina.
31: When Nina notices it, the reflection in the mirror behind her moves faster than Nina herself.
32: Curiously the green painting is the one Nina's mother is correcting few scenes later.
33+34: The club scene: Rothbart appears several times.
35: The club scene: Lily is seen embracing him.
36+37: The Black Swan doll is the only black toy in Nna's room. Later on when she is getting rid of her stuffed animals, Black Swan falls on the ground and Nina doesn't pick him up. All the other toys end up in the trash chute.
38: The shadow of the wings.
39: White swan figurine next to Nina's bed.
40. The swan can be seen on the sponge behind Nina.
41: The club scene: In one frame there is a tiny ballerina dancing with moon on the background - it appears to be the same as Nina dancing her final performance in the ending of the movie.
42: The club scene: Right before Nina and Lily hug, they both appear to be the same person.
43: The club scene: When they hug things around them appear to become more and more creepy and distorted.
44: In the sex scene Lily turns into sinister looking Nina.
45: When Beth is stabbing herself in the face she suddenly turns into Nina with bloodshot eyes.
46: When Nina screams, ALL the paintings scream with her.
47: The club scene: Nina and Lily's hands, multiplied.
48: The club scene: Nina in various stages of despair.