Wasn't there also a difference in a lot of people's minds between a woman who was naked and the implication being she was always naked (that picture of Venus,) and a woman who was naked with her clothes in the picture implying she took them off? (I can't remember what picture I'm thinking of for the life of me)
That is one aspect, yes! There are a lot of different types of nudity in art and they vary by degrees how well they're received by critics. There are "holy" depictions (a breastfeeding Mary, a nude Jesus on the cross) that are generally acceptable but still often censored, and nowadays it might actually be even more controversial to depict nudity in biblical art despite the historical equivalents being (for the most part) accepted. You brought up Venus and the one people think of, I think, is Botticelli's Birth of Venus, 1486. Her pose is fairly modest as in most mythological paintings around that time, BUT it calls back heavily to ancient statues of Venus, ostensibly making it kind of an ode to ancient art and less a depiction of the female form. This isn't about sculpture vs paintings but it should be said that art form and historical perspective play a large role in what we consider tastefully erotic or blatantly scandalous.
Slightly more modern Venus is Rokeby Venus by Diego Velazquez, which has Venus turned toward a mirror. This one was still controversial, more voyeuristic than a couple of centuries prior, and more typical of the nudes of the 17th century. Venus as a woman rather than a mythological figure is still a source of criticism.
The painting I think you're thinking of (if it's not Baigneuses) is Goya's The Nude Maja, which is frankly one of my favorites. Very in your face, "this is a body", daring. And super super controversial back in the very early 19th century. She's not a myth or a holy figure, she's a bare woman who is as much of an exhibitionist as the viewer is a voyeur. Look up the full history on her, it's honestly fantastic.
Courbet still takes the cake for controversial nudity, all considered. He basically took the overwhelming criticism about drawing tits and turned it into energy to aggressively draw more tits. The Origin of the World still pisses people off and I am living for it.