First Amendment rights are relevant here only if it turns out that LiveJournal has made the policies it has in order to comply with U.S. law; if they have, it then matters whether the law is constitutional.

Try support@livejournal.com. They may punt it to the public support board, but probably not; in fact, if you went through the board, it would probably wind up in support@

I also suspect they'll be more likely to answer a question of the form "what body parts must be concealed, and does this apply to drawings as well as photographs?" than to one that says that their answer to that is ipso facto wrong.

Now I'm wondering about California law, given that Six Apart is located there. In New York State and Ontario, women are allowed to go bare-chested precisely because of the "must apply to men as well" argument: when the courts ruled that requiring women to cover our nipples was only acceptable if it applied to men, the relevant legislatures decided not to go there. (NY's ruling was based on the state constitution, so (a) it doesn't affect any other state, and (b) there was no basis for appeal to federal courts. I think Ontario's is based on the Charter of Rights and Freedoms, but you might want to consult a Canadian if you care.)

[The above is the closest I have to a nude userpic.]