I'm another one who is generally cautious about gender bias claims, but there's a context here that makes it more bothersome. Heck, you can go back to the OP and the other woman's strange assertion right off the bat that she's a fashionista. Even that could be feeding into it. If boss is assuming the OP is another fashionista, and/or he's stereotyping that all ladies dig convos about shoes, and men talk about real things like cars and football, this stuff can add up. And then "ladies" becomes something else.