I don’t know why, but if was seeking to identify someone I think I’d say “gay” rather than “lesbian” too. For some reason it just sounds a but less rude to me, but I’m not sure why. Or I guess we have “the woman who wears comfortable shoes” to fall back on!
I don’t think there’s any fundamental issue of bigotry involved here (unless you are seeking to identify someone for that reason). It’s just a question of politeness, because someone’s sex life is generally none of your business. However, if someone does choose to represent their orientation in a particularly unambiguous way - I think we’re talking about the female equivalent of the flamboyant/camp gay male presentation - then I don’t think it’s all that impolite to use this as a way to identify them.