- Alternate Character Interpretation: The reason Marie's mother refuses to take custody of the baby - does she realise that Marie won't be granted parole and she might have to take on the child permanently? Is she more willing to take it on, but afraid of angering her husband? Or is it simple worry about her reputation if she has to raise a grandchild who was born in jail?
- Award Snub: Agnes Moorhead gives a very understated but powerful performance as Ruth Benton, and didn't even get a nomination.
- Catharsis Factor: After seeing Harper abuse the inmates throughout the film, the viewer is bound to be cheering with them when Kitty finally stabs her to death in the mess hall.
- Hilarious in Hindsight: Seeing Eleanor Parker having to give up her baby is sad, but becomes amusing when you see her in another film where she's terrified at the thought of being a mother to seven children.
- Narm: The kitten's mouth is clearly moving when it's pronounced dead.
- Nightmare Fuel: Evelyn Harper is one of the most terrifyingly cruel prison wardens in film history. Part of what makes her so terrifying is that she knows she can get away with everything, and Ruth Benton is powerless to stop her.
- Moral Event Horizon: Harper first flirts with crossing it when she taunts June about being denied parole, resulting in the girl's suicide. But she definitely crosses it when she goes behind Benton's back to forcefully shave Marie's head.
- One-Scene Wonder: June is barely in the film but plays a significant part, emphasising Harper's cruelty. Her suicide gives Marie a huge reality check - and serves as a warning not to get her hopes up at being granted parole.
- Stoic Woobie: It's easy to see Ruth Benton as this. She's doing her best to fight a corrupt system and a matron who undermines her every order - and gets away with it too. She's determined to treat the girls like people and not animals, but it's unclear if she's actually getting through to them. She even sounds so defeated in her final scene with Marie.
- Tear Jerker:
- Marie's devastated reaction to her mother refusing temporary custody of the baby - out of sheer selfishness - especially since the other option is to put the baby up for adoption. In a fit of hysterics, she tries climbing out over the prison fence.
- The death of the pet kitten and Marie's subsequent punishment headshave. The kitten was a Morality Pet for her and its loss and her following humiliation result in her final FaceHeel Turn. Her tearful "all I wanted was the kitten" cements it.
- Marie tossing her wedding ring away before she gets out at the end. She clearly did still love her husband when she came in. But she has now come to only resent him for landing her in prison in the first place - showing how she has become completely broken by her time inside.
- Unbuilt Trope: Just like its competition So Young, So Bad, this is the Ur-Example of Girls Behind Bars. Yet it is a film noir instead of exploitation, the abuse is played for Nightmare Fuel and the story is genuinely dark and grim.
- Values Resonance: The film is remarkably feminist for a 1950s production. Not playing the female prison setting for any Fanservice or titillation, the film's themes about corruption and crime are still relevant in the modern age. Evelyn Harper's abuse of the inmates (that no one bothers to stop) parallels things which are reported today too.
- Visual Effects of Awesome: Eleanor Parker did not really have her head shaved on-screen. Not that you'd know it, because the effect is very convincing.
- What Do You Mean, It's Not Symbolic?: The Traumatic Haircut and the argument Ruth Benton has with the bureaucrats about it has been interpreted as a metaphor for Prison Rape. Especially how Benton states that no man can ever truly understand what doing that to a woman means to her. The fact that it pushes the victim over the Despair Event Horizon solidifies it even further.
- The Woobie:
- Marie Allen, an innocent 19-year-old forced to prison for crimes she was only an accomplice for. She's sent while pregnant and just after she's lost her husband. The Trauma Conga Line the girl goes through is a hard one.
- June too, convinced she's going to get out. When she's denied parole - and mocked for it by Harper - she opts to kill herself rather than stay in.
YMMV / Caged