I'd say Spartacus TV series on the Starz network is doing slave girl imagery about as well as any mainstream source ever has. Here we have a naked, barbarously bedecked slave girl being used sexually for the amusement of Romans. That's a slavegirl! Nothing like it on the Youtube channel, of course. Source: vidcap from Spartacus TV series, episode, "Legends."
Looking at the comments section of this blog, I found a reference to a Youtube channel called Slave Girls that was being started up back in 2010. It's basically a bunch of mainstream scenes of slave girls on television, and on the sort of movies that could be shown on mainstream television uncut. There's a sort of goofy humor to them, especially the stuff from Hayes Code era movies and 1960s television, when slavegirls could be sexy but not in any way that could make you understand their sexiness, other than being attractive and female. There's not a lot of actual bondage (I think a scene of Jasmine in chains from Aladdin and a video of image of Slavegirl Leai from Star Wars is about it) and no sex, as you might expect.
There's also some wrestling videos that are more problematical, images of women on their hands and knees so burly wrestlers can use them as a stepping stone to get into the ring. I'm not sure what to make of them except, you know ... wrassling ...
Check it out, see what you think.