So the problem I have is this:
I get a little gas when I see others judging someone's personal tastes that harshly. She's not wearing crotchless panties (assuming she has any on at all!) while uncrossing her legs. There's no cutouts on the front for nipple clamps. No abortion pictures, political slogans, or animal blood splashed across the front.
If she came to the wedding dressed like that, acted respectfully to the bride and groom, didn't get drunk and loud, and didn't bang the best man in the confessional, then I'd say the people with the respect problem would be the ones who tossed her out, not the one (gasp!) wearing that dress.
What is so mind-numbingly important about the clothes on one's back that make you want to eject them from a wedding? That's what I don't (and probably never will) understand. I'm reminded of Joe Pesci in "My Cousin Vinny".
Then again, I would never patronize a restaurant that wanted to rent me a jacket before sitting down either. I'm way more interested in the person than in what they choose to wrap themselves.
The problem is that by coming to the wedding dressed like that, she has already behaved in a disrespectful manner to the bride and groom. She can behave politely in other ways, but the outfit would be viewed as disrespectful by pretty much any church going community, people of many other cultures that value modesty in dress, and people who just simply take manners seriously.
I'm sure that here in the Midwest, the offense would be classified as a misdemeanor. In the Bible Belt, it'd probably be a felony. And in places like LA, New York, or Miami, it wouldn't even register.
Like it or not, people look at the way a person is dressed and how they present themselves before deciding if they want to strike up a conversation. Maybe not all, but I'd say a vast majority. It's what we do.
If I saw that woman at a club wearing that dress and she seemed interesting somehow, I'd chat with her to see if she really was interesting. If I saw her at a wedding wearing that dress, I'd avoid talking with her for 2 reasons. 1) It's rude and could be attention seeking drama queen behavior. No, thanks, I have daughters. I don't need any more of that in my life. 2) I don't want to get hit by the tar and feathers.
Besides, there are many styles of dress she could have worn that would have been equally sexy and not nearly as tasteless.