I started listening to the oral argument in Frontiero v. Richardson. In those days, the argument audio picked up some of the chit-chat among the Justices on the bench. At the start, you can clearly hear someone (most likely Chief Justice Burger) saying “short skirt” repeatedly. Here is the link
I can’t say for sure to what or who this comment refers. But Ruth Bader Ginsburg was sitting at counsel’s table and would soon make her argument. In any event, it’s a rather odd kickoff to an argument on sex discrimination.