But an important point is getting lost in this discussion. Every community has their standards, which is why international tznius organizations (or even national) are going to confuse or upset people who adhere to the standards of their own community, but are being pushed to accept the agenda of another community. We need to respect one another, yes. Not necessarily to accept the standards of others as our own.
We were once on the way to the Catskills the week of the yahrzeit of the Satmar Rebbe zt”l. We are not at all chassidish but I though it would be a big zchus to go daven there. Then I realized I was wearing 3/4 sleeves. This is totally acceptable in my community but I felt it was wrong to go in to a community where it is not acceptable (in fact I believe it may be ossur to go somewhere if your dress does not adhere to minhag hamokom).