Fashionista

In the bathroom at Applebee's and a server says to Kendra, "Oh what a pretty girl!  I like your skirt!" Kendra raises her eyebrows and scowls at her as the lady leaves the restroom.

 "Kendra, that wasn't very nice.  What do you say when someone says they like your skirt?"  She looked at me and said, "I say, 'It's not a skirt, it's a dress."  And then she turned around and walked out of the restroom. She was correct, but I think she's still missing the politeness point...