I don't thing that a nude photo may be classified as "perverted" because it's natural (people were born nude, the animals do not wear clothes, etc.) and it's related to the normal libido.
But I do not understand WHY there are people who would ask for something like this when there are so many classical and modern, and even contemporary photos of nude people online. That's not normal.
Well, if you know somebody and you really, really like her, maybe it's normal to want to see
exactly this person, not others. But if she is just "one of them" then why not searching for some erotical or other nude photos instead to bother that girl?!
By the way, I am a male but I also do not like to post or send my nude photos.