* AdaptationDisplacement: Not many people know that the film is based on a short story.
* EpilepticTrees: The remake leaves us wondering if [[spoiler: Dahlia was imagining the whole haunting due to her stressed mental state, along with accusing Kyle of being "abusive" despite no implication of it.]] As for why [[spoiler: Ceci could see her mother at the end of the film despite being dead could be Ceci herself having gone a bit crazy after what she's endured from Dahlia's paranoia]]. There's a possibility Dahlia could have suffered from schizophrenia due to her abusive childhood and seemed to have passed it onto Ceci, but it's unknown if that's the case.
* HarsherInHindsight: The events of the two movies bare a disturbing amount of similarities to that of Elisa Lam in 2013. Lam's body was found in a water tank in a Los Angeles hotel - Hotel Cecil, similar to Ceci's name. The body had been left to decompose for as long as 19 days while unknowing guests drank, bathed, and brushed their teeth with the tainted water. Despite being ruled an accident, many unsettling theories sprang up when one of the surveillance videos taken of the woman's last moments had her acting [[https://www.youtube.com/watch?v=3TjVBpyTeZM strange]] and anxious in a malfunctioning elevator, as if being followed by someone or even something (although now it's theorized it was because she had a mental illness).
* MoralEventHorizon: Veeck crosses this in the remake. He ''knew'' about [[spoiler:Natasha's decomposing body in the water tank]], but decided to leave it there because, in his words [[spoiler: "It wasn't his job".]]
* NauseaFuel: The water in the apartment is known to be dirty by the residents - Yoshimi even finds a hair in her glass of water early on. The reason for this? [[spoiler: There's a ''decomposing corpse'' in the water tank.]]
* TheWoobie: Yoshimi and Dahlia. Ikuko also becomes one.

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