They would all be flying with empty planes if they started playing fashion police, like they did in San Diego this week.
This woman is dressed modestly by Devushka standards. Those are MEN'S shoes, for crying out loud.
If that airline hopes to compete against Aeroflot, AeroSvit or even AeroDon (which btw, given Southwest's service standards, is a pretty fair match in the marketplace), they might want to dump the passenger dress code.
Southwest may not know it yet, but they are totally the official Devushka airline.
Carpetblog suggests: Southwest Airlines! Embrace your inner devushka. Is there that big of a difference between the LAX-LAS and KBP-IST commuter flights? No, there is not. Do a little market research. Don't fight it and stop trying to be something you are not.