I don't think that's correct, there is no reference to nudity or not. The text is:
I am not a lawyer, obviously! Heh.
Going back to the original story (can't remember where else I read about this as it was last year):
https://www.bbc.co.uk/news/magazine-40861875
The police finished by reassuring me that they had "made him delete the picture". At this point, because of the mess I was in, it didn't occur to me that this was my evidence.
The photograph wasn't considered graphic because I had knickers on - if I had chosen not to wear any underwear it might have been dealt with entirely differently - but I don't see how what I was wearing should affect their response.
That's the bit that made me think voyuerism wasn't an option. But then again that's the opinion of police officers and they're not lawyers either!