Warmly, Elsa tells her, "Casual's just fine." After all, she's been pulled away from her kingdom. What's the queen of Arendelle without Arendelle? There's no ceremony here, no reason to ask anyone else to put on airs. "We don't keep a very formal palace. My sister, Anna, is very--" how does she put this? "--personable."

The way it's said, with deep affection and even admiration that comes through despite the awkwardness, places the comment squarely in "compliment" territory.