“No, oomis, that is halacha not a chumra. “
I never said it wasn’t Joseph, so please do me the courtesy not to put words in my mouth. Obviously a picture that is l’chatchilah not a tzniusdig one, is an issue of validity, and perhaps OS SHOULD address that, if enough people complain to them. But there is no halacha that it is not tzniusdig to post a picture of a man and a woman, and if there is such a chumrah, then it is not one that msot people seem to hold by. Anyone who wishes to avoid seeing pictures is perfectly free NOT to visit a site where pictures of simchas are posted. I totally agree with that. But just because your concept or someone else’s concept of tznius includes not seeing a picture of a woman in any publication, that does not make it something that the rest of the frum Jewish world has to accept stam azoy. I agree that some pictures of women (and men) are not appropriate. But you do not throw the baby out with the bathwater. You clean up the bathwater.