I'm not certain what came first. From what I've read women during this time period wore dressed because it was thought to reduce the chance of infection when bleeding from the vulva. When absorption pads were invented women could wear pants without worry. I know that the Irish and Scottish wore Kilts. I'm not certain what the Romans and Greeks wore. It didn't appear to be very much. It does look like the elite wore dresses or robes. More primitive people appear to have all worn loincloths of some sort aside from the Eskimos. If the bushman are examples women didn't wear tops. There are so many different cultures with different clothing that it's difficult to say. Many cultures in the 1800s seemed to have women with dresses and men with trousers. It may have been more for practicality at the time rather than any kind of identification with some vague idea of what they are. Clearly in this instance she is modeling herself after a man which may or may not have been a wise decision depending on varying factors at the time about how practical it was. Of course the Native Americans appear to have allowed women to identify as masculine or take on more feminine tasks. I'm not sure if this included the person wearing male or female clothing. I don't think it's as large an issue as people make it out to be honestly. It may comfort people to think about things a certain way and that's okay I guess. It's more of a luxury though. If we lived the old way we would be to busy trying to survive to worry about sexual identification or clothing other than it's practicality too much.