Jeff (James Stewart) is a character bachelor. A phone conversation near the beginning of the film where he says ““If you don’t pull me out of this swamp of boredom, I’ll do something drastic - I’ll get married” gives us an instant glimpse of the lifestyle of solitude Jeff treasures, and establishes themes for the film. He carries on watching out his window, making observations about the other residents of the block, drawing inferences about their lives.

The first image we see of Jeff’s love interest Lisa (Grace Kelly) is a negative film slide, a shot that characterizes Jeff’s negative feelings about marriage.

All of his neighbors serve as variations of his own hesitancy about committing to marriage. We see loners representing the despondency of solitude, newlyweds cajoling with the adventure of a fresh marriage, and the burdenous responsibility of caring for another if they grow ill. Jeff’s identification with each character expands as the film progresses, each apartment window serving as its own little play-acting of a different compartment of Jeff’s whole self.

TCM says, “All of the lives Jeff observes from his rear window have one common denominator; they all in some way reflect different aspects of love and relationships. They all have a bearing on Jeff’s view of love and marriage. Even when Lisa goes into the murderer’s apartment, the proof she finds of his crime is his wife’s wedding ring, which she places on her finger and points to for the benefit of the watching Jeff. On one level, she’s letting him know she found the vital clue; on another, she’s challenging him (now that she’s “proved” herself) to stop coming up with excuses and marry her.”

Jeff furthers his character setup through dialogue with his caretaker, Stella (Thelma Ritter), who is trying to tell him he’s stupid for not wanting to marry Lisa. Jeff uses the excuse that she’s too perfect, too classy, too high-society for someone like him, which Stella dismisses as nonsense.

Lisa is offered up as an exhibitionist. When we first see her, she’s introduced beneath some ridiculously expensive gown. She poses in front of Jeff and tries to woo him. She’s clearly used to being stared at, yet Jeff is interested in peering at everyone but her.

A scene approaches where Jeff watches Miss Lonelyhearts across the way, setting a table for two, pretending a man is going to join her. As he’s watching this, Lisa is behind him, setting the table for an actual romantic evening, one which Jeff is ignoring to watch the neighbors.

FilmSite.org examines this section of the film in depth: “In the next part of their revealing conversation, Jeff points out a similarity between the apartments of Lisa and the in-shape young dancer dubbed ‘Miss Torso’ (Georgine Darcy) [nicknamed with a dismembered body part, a strange name given the subject of the film] who is serving drinks and entertaining three male suitors in her apartment. In the midst of their own domestic crisis, both of them use the experience of viewing ‘Miss Torso’s’ apartment to make cutting remarks toward each other about their own strained relationship:
Jeff: ...but we have a little apartment here that’s probably about as popular as yours. You remember of course ‘Miss Torso,’ the ballet dancer. She’s like a Queen Bee with her pick of the drones.
Lisa (changing the metaphor): I’d say she’s doing a woman’s hardest job - Juggling Wolves.
Jeff (watching ‘Miss Torso’ briefly kiss one of the men on the balcony and attempting to go back inside while he restrains her): She picked the most prosperous-looking one.
Lisa: She’s not in love with him or any of them.
Jeff: How can you tell that from here?
Lisa: You said it resembled my apartment, didn’t you?”

This parallel continues for the rest of the film. The actions of Jeff’s neighbors are continuously entwined with his conversations with and feelings for Lisa. It’s not until the ending when she puts herself on the line that Jeff is able to appreciate his real feelings for her.