“shivim panim leTorah.”
unfortunately, none of those panim condone dressing in a way halacha forbids or viewing things halacha forbids. this entire discussion smacks of the very xtian concept “let he who is without sin cast the 1st stone”. I am not saying one should react violently, or throroughly embarrass or otherwise ridicule someone doing something that is against halacha, but to smile, shrug ones shoulders and say “shivim panim litorah” and “who am I to judge” is also a distortion of yiddishkeit. As in all things in life, when you encounter a situation and are unsure how to proceed, consult a rav/rebbe/madricha/rebbetzin or whatever it is you call this person.