She was just doing it instinctively. She was really trying to pretend to be a princess and she was just the natural queen she totally is. And she actually got so embarrassed, because that’s like saying she’s not girlish and whatever.
And it had to be Rin. Of course it did. Because only Rin would say it so bluntly and take so much joy it and only Rin would embarrass Karen this much.
This whole scene has been amazing since the very first “Onee-sama.” I’m the happiest girl in the world right now.