BS”D
Doc: What part of “obviously shomer Torah u’mitzvos do something pleasant or harmless that I might not do myself,” did you not understand?
A skirt like that is neither pleasant nor harmless nor would I even assume someone wearing it was shomeres torah umitzvos (because chances are her shaitel is so long and natural looking as to fool me or her hair is also not befitting a bas Yisroel).
That is assuming I would somehow notice such a thing. Usually I don’t pay attention to womens’ skirts………………….