Eh, I'm not so sure.
Nude these days means (in the case of a woman) that her nipples and crotch are showing with no significant covering.
Breast skin (other than nipples) is not considered "nude". Butts are not considered nude, they even show up on FR.
Is a woman who is completely dressed except that her nipples and crotch are visible considered nude?
The terms become very ambiguous when you dive into the details.
All I know is, I know it when I see it. LOL
At my age, I can’t get lost in the details.