I agree completely. That was why I suggested the public place standard. What you said is a better standard, but harder to avoid subjective enforcement.
What you wore to visit your adviser seemed appropriate. It reminded me of a friend who, in the 1970s, told me that he went job hunting with a beard because it kept him from getting a job somplace that he wouldn't want to work.
The undergarmet that became an outer garmet that I was thinking of was the muumuu. Here is a quote from http://www.aldridgeshs.qld.edu.au/sose/modrespg/imperial/group1/settlers.htm
that explains the history.
"Hawaiian royalty began to imitate Western habits, in some cases traveling to Britain and often building Western-style palaces. Two powerful queens advanced the process of change by insisting that traditional taboos subordinating women be abandoned. In this context vigorous missionary efforts from Protestant New England, beginning in 1819, brought extensive conversions to Christianity. As with other conversion processes, religious change had wide implications. Missionaries railed against traditional Hawaiian costumes, insisting that women cover their breasts, and a new garment, the muumuu, was fashioned from homespun American nightgowns with the sleeves cut off. Backed by the Hawaiian monarchy, missionaries also quickly established an extensive school system, by 1831 serving 50,000 students from a culture that had not previously developed writing."
My memory, based on what I was told by a friend whose grandmother was pure Hawaiian, was that it had been the women who had converted it from an undergarmet to outerwear, but this account leaves who did the conversion ambiguous. That friend also told me stories that I have since learned are not supposed to be told to those not of Hawaiian blood, so I suspect that the version I heard was the true one.