While in the game itself, it seems more like a mocking tone (e.g. lmao, you're so pissed over your house)... I do like the idea here that Sunny is legit confused why Cirno's so determined over a house.
Fairies are carefree. They don't linger. They naturally move on to the next thing that grabs their attention. Hell, Cirno admits in response that the house itself ain't shit. It's not about the igloo. It's about the WAAAGH!
Context – Great Fairy Wars, Route C-2, Stage 3
