Continuing a discussion ZkinAndBonez and I were having in another thread: apparently Ralph McQuarrie did some concept art of NSFW Leia outfits for the prison escape in the original Star Wars. See here, here, here, and also here.
In the first image, Leia’s clothing is just a loincloth, and she’s naked from the waist up. The same thing is true in the second image: the loincloth is pencilled in more lightly this time, but Leia is covering her exposed breasts with her right arm. And in the third picture (a detail from the frontispiece in The Making of ESB, though it was actually done for SW 1977), her top has partially slid off during the Imperial torture droid’s interrogation, exposing her left breast.
The fourth image is more debatable, but I think it shows Leia wearing a nipple chain under her tunic, likely inspired by a line Katharine Hepburn has about wanting to wear one in The Lion in Winter.
Contrast this image, where Leia is wearing a much more demure outfit, apparently consisting of a pair of pants and a midriff-baring tank top. So McQuarrie did indeed draw costume concepts in some of these storyboards.
Is there textual support for this sort of nudity in SW? I think so.
The 1974 SW rough draft includes a scene where Annikin Starkiller and Princess Leia are separated when they land on the jungle moon of Yavin. When Annikin catches up to her, Leia is the prisoner of nine “Ureallian trappers”, and is “half-naked” and unconscious. It’s implied they’ve sexually assaulted her.
JW Rinzler apparently thought so, but preferred not to spell it out explicitly: in one blog post on the official SW site he wrote “In the original 1974 rough draft… the “trackers” are nasty aliens who live on an Ewok-free planet known as Yavin. I don’t want to say what havoc they cause, but it isn’t pretty.”
The 1975 third draft similarly has Leia suffer a hands-on interrogation from Vader and two Imperial officers, which may be based on a scene in the THX 1138 novelization where LUH 1417 is assaulted by three guards during her imprisonment. If something similar happened to Leia, it would give Lucas a good reason to tell Ralph McQuarrie to draw her bare-breasted.