Thread:ChishioKunrin/@comment-26397825-20160516204412/@comment-26397825-20160516213708

Well, a curtsy is a thing that everyone did to show respect to those of a higher station. So it was good manners and polite behaviour to greet people with a curtsy. For those of a lower station, it was common courtesy to curtsy to those of a higher station. And it wasn't just for the common folk either; everyone did it if they met someone in a higher station.

It fits both meanings, really.