@Krune Nah, it was her thought of how Utako smells so good compared to the ghost. Also, at no point did the ghost say she smelled good. The first page shows she could smell evil spirits by their stench since forever. Then, on page 3 there's the sniff (untranslated くん) just before the "!" of realization.
The chat about them, though, is so off. The others are not talking about how Utako differs from before, but noting how she's extra "different" in her own way that's not the same as Mirei. So, while Utako is the hyper, hyper overreacting type, Mirei is the way too cool poker face one.