A priori, what is not legal, is an attack against modesty (what is modesty? it's a philosophical matter, knowing what modesty is!) and that's the reason why laws were created.

For one thing, modesty is ill-treated every day in a more criminal way on posters or advertisements that show women (and more and more men) half nude, overexcited or visibly in lack of sexuality, since they caress themselves (for example advertisings for perfumes) or suck ice-creams (for example the advertising of miko), with a clear allusion to sexuality.

It is more impudic, it seems, to hide a part of the body while attracting the attention on it ( that's the effect of slips, panties and bras) instead of showing yourself like a nude 'total' , without sexual intention -whereas sexual intention is madly present in advertisements.

Consequently, we won't go against the law if we do not go against the goal of the law.