There is a basis for Cynthia and Carol in Diane's waking life — DeRosa/#12. The answer lies in her function: to serve as a contrast to the object of obsession, to serve as a more practical or suitable choice over the object of desire... — Neely O'Hara
The neighbor — Diane's real lover?
Did anyone notice that the woman who lives in apt #12 of Sierra Bonita is a lesbian? Notice the way she is checking out "Rita" while standing in the doorway. Plus, she carries herself in the stereotypical "dyke" style, with her rough/tough image. My opinion is that Diane and this girl are the ones having the lesbian encounters and not Diane and Camilla. After all didn't Diane originally live in apt #12 with the lesbian girl, before moving out to apt #17. Diane is only substituting Camilla in place of the lesbian lovergirl to fulfill her sex fantasies. Diane imagines that it's Camilla who says, "we can't be doing this anymore." Thus driving Diane deeper into her jealous, delusional state. Camilla was never there. — FilmflamMan
I think Diane and DeRosa definitely had a serious relationship; it was evident from their interaction and dialogue. Also, DeRosa and Camilla's similarity cannot be ignored. It seems like DeRosa is a more 'plain' version of the beautiful Camilla. Hence, I contend that, knowing she could never have Camilla as she desired, Diane went after DeRosa as a substitute. During their perceived relationship, Diane still occasionally got down n' dirty with Camilla. When DeRosa figured this out, that's when they broke up. — Cuban Nightmare
I used to think that Diane had basically done to the other woman what Camilla had done to her. They were together, then something better came along (Camilla), Diane dumped the other woman and went with her. Camilla ends up doing the same to Diane. Diane is so hurt, but also a hypocrite, therefore adding to her confusion and pain. — akin-2-grieve
Related: Camilla not Diane's lover?
Regarding the lamp lady thing, I see a similarity in Diane's actions and demeanor in this scene as well as some other scenes. Diane seems forceful and has a sense she is in control:
- The scene on the couch. Diane is the forceful one.
- The scene at the doorway, Diane is controlling Camilla, making it hard for her.
- The scene with the lamp lady. Diane is annoyed and short with the lamp lady.
- The scene where she contracts with the hit man "More than anything in this world".
I think these scenes go together in this order and the lamp lady is Camilla. The thing missing in this story is Diane actually kicking Camilla out. Well we have another scene showing just that. — beth elms
De Rosa was into something sinister in the pilot/series thus the evasive looks and strangeness. I believe there is some connection between aunt Ruth and De Rosa because of their similar clothing and checking of an apartment they are leaving or recently left and is occupied/to be occupied by Diane/Betty. — richdubbya
Tangled identities
— Darklite
I'm going to hit you with something. DeRosa is not DeRosa. And Diane did not switch into #17. There are a number of clues that support this theory:
- In the film credits, many characters have names that are simply not mentioned in the film. However, W. De Rosa's character (her name is clearly seen as occupying #17) is listed only as Woman in #12. This is Lynch telling us she is not who she seems. Remember, her name is never said.
- When Betty and Rita are walking towards #17, we see each of them inexplicably look at the apartment next to it: #16. A POV shot of the apartment shows that the outside light is on, yet it's the afternoon. As they pass the apartment, Rita brushes past a flower, which is clearly pointing to apartment #16.
- So who lives in #16? Someone named A. Gonzales. In the listing of names in the West Courtyard, Gonzales's name stands out from the rest because it is highlighted in yellow. DeRosa and Gonzales are both Hispanic names, and the woman we believed was DeRosa looks a bit Hispanic.
- At the Park Hotel, Adam is staying in #16. Cookie (who is Hispanic) tells him two guys were looking for him and that whoever he's hiding from, they know where he is. My theory for the "real scene": In apartment #16, Gonzales tells her two detectives came by again looking for her, making Diane think that sooner or later they're going to find out where she is.
- The number 16 pops up at least four times in the film: "1612 Havenhurst", "16 Reasons Why I Love You", Adam's hotel #16, and the highlighted apartment at Sierra Bonita. The number 17 doesn't fit in with the rest of the film; it's supposed to stick out like a sore thumb.
- Notice the different hairdo in dream and reality. Her hair is different because Camilla/Rita cuts her hair in the first part of the film. These characters are inextricably linked. — blu
- DeRosa is almost an anagram of Rhodes. Rhodes (Rodos) is the Greek island of roses. DeRosa is Spanish for "of/from rose" → further connection to Camilla?
- On the apartment listing at Sierra Bonita, the name next to #17 is L.J. DeRosa — a member of the film's art department, Laura J. DeRosa.
- The buttonholes on De Rosa's shirt are on reversed sides in dream and reality. → compare. A hint to her bisexual nature?
Possible connection to Herb shouting "Dan... are you alright?"
My theory is that De Rosa knocks on the door and says, "Diane, are you alright?" at the same time that Diane is asleep and in the process of dreaming the scene in which Dan dies. De Rosa then goes back to her apartment, but eventually becomes irritated at Diane. She comes back a second time, about an hour or so later. This time, she really pounds on the door and wakes Diane up. That's why De Rosa is in such a crabby mood when Diane opens the door — "Where have you been?" In other words, "Dah-ann, are you alright" is Diane's perception of a real-life sound in real-time, while she is dreaming. The symbolism is that reality begins to creep into Diane's dream from the very beginning, as it continues to do throughout the dream when this process culminates in the disappearance of Rita. — Rusty Nail