Gaffes

(at around 19 mins) When Nell and Theo first meet, Theo puts on her leather jacket. In the following shot, Theo's reflection can be seen in the mirror behind Nell, and she puts on the jacket again.

Eleanor falls asleep in a double bed, then wakes in a twin bed.

(at around 22 mins) When Nell and Theo first find the mirror/carousel room, they step onto the revolving floor twice.

(at around 43 mins) The curtains of Nell's room clearly aren't long enough to cover the bed as shown during the first night at Hill House.

(at around 45 mins) When Nell is doing the puzzles Dr. Marrow gave her, the first two we see are done with a green magic marker, yet we saw her using a pencil.

(at around 1h 25 mins) Later in the movie when Eleanor is trapped in her bed, the ceiling of her bedroom is visible. There is a circle-shaped part of the ceiling with zodiac signs on it, but the zodiac is wrong. There are more than 12 parts (number of zodiac signs) on the ceiling. Also, in the first shot of the ceiling, some signs repeat, the order is wrong, and the Cancer sign is mirrored.

(at around 1h 35 mins) The strings pulling Luke on the carpet are briefly visible.

(at around 1h 30 mins) When the oval from the gate falls on Nell's Gremlin, Dr. Marrow and Theo struggle to lift it from the car, but as Luke jiggles the door from the inside, one can see that the spikes are rubber, as they bend against the door.

(at around 1h 2 mins) When the spirits are moving Nell's hair, she jumps up and bumps a hanging lantern, causing light to alternate on and off her face. She steps forward, putting the lantern behind her, but the light on her face still alternates.

As Nell is working on her assignment near the fireplace, Luke leaves the room and shuts the heavy "Gates of Hell" door behind him. Nell is suddenly startled at the appearance of Hugh Crain's face growling at her from the fireplace and runs out of the room screaming. Next, the group pushes open both heavy doors to investigate. Nell didn't have time, nor would she have taken the trouble, to stop and push the heavy door closed behind her as she fled in terror.

(at around 2 mins) When Nell's nephew Richie knocks a doll off the table, the doll is heard being knocked off twice.

(at around 1h 15 mins) When Nell is pulled off her bed whilst witnessing the windows changing, the string pulling her is briefly visible.

(at around 1h 18 mins) As Nell runs away and tries to hide in the carousel room, the camera passes behind a pillar in an overhead shot. Just after that, the reflection of equipment is seen in one of the mirrors on the right side of the screen.

(at around 5 mins) When Nell sees the advertisement in the newspaper, it says "in Berkshires," but when driving to Hill House, she looks at a map that clearly shows Central Massachusetts.

The exterior shot of Nell's home is clearly a block of flats in England. As a token attempt to pitch it as being in the United States, an American pickup truck pulls into the car park.

After the portrait of Hugh Craig is marked up with red paint, it is said that, "Mrs. Dudley will take care of it," and the effort to remove the paint is seen later. However, the Dudleys left early on with Mary and Todd to get help. Additionally, they locked in everyone who remained in the house from outside the gate.