- Alternate Character Interpretation: Since Helen doesn't run screaming from Mark once she discovers the truth, maybe she has a bit of a Nightmare Fetishist side to her - and she and Mark are Not So Different. She notably becomes attracted to Mark after seeing the videos of his father scaring him. Or maybe her attraction to him is rooted in feeling sorry for him? As a writer herself, she might be attracted to his tragic childhood.
- Crosses the Line Twice: The star of the film Mark is working on has a reaction to seeing a red hat (after they've found Viv's body). She has a hilariously over the top scream, and the director is more annoyed about the filming being delayed again.
- Nightmare Face: Staring at yourself as your inevitable murder comes upon you.
- One-Scene Wonder: Viv only appears in the middle of the film as Mark's second victim. It adds up to about fifteen minutes of screen time. But she's such a lovable Genki Girl that it makes her demise all the more tragic.
- "Seinfeld" Is Unfunny: Some find it rather genteel by modern movie standards. Given the use of the Gory Discretion Shot (which was mandated by censors) it can be surprising to find that this was so controversial.
- Unbuilt Trope: The originator of the Slasher Movie puts the audience entirely in the killer's POV. The Death by Sex applied to his victims is justified by the circumstances - he wouldn't be able to get so close to normal everyday women. And the Final Girl doesn't get killed like the rest because the killer is actually in love with her.
- Values Dissonance: When Helen watches the video of Mark spying on the kissing couple, she says "I hope you were spanked for that" - right before she objects to Mark's father scaring him all the time.
- Vindicated by History: Viewed as trashy and exploitative at the time, it's now seen as a classic of the horror genre.
Michael Powell: "I make a film that nobody wants to see and then, thirty years later, everybody has either seen it or wants to see it."