What makes a person カラッと?

Question

I'm reading a manga. Two sisters have just lost their father. Sister A laments that she doesn't know what to think, and sister B is just staring into the void. Then sister A says to sister B

やけにカラっとしてるじゃないか。

Question: what on earth does she mean? In the dictionary, I find "dry", but that doesn't make much sense. Googling around, I've also found 明るい, but sister B doesn't look happy. My interpretation would be "You look like you don't care at all." or something like that, but that doesn't fit any dictionary entry I've seen.

Answer 1

「やけにカラっとしてるじゃないか。」

Your interpretation of "You look like you don't care at all." is actually spot-on.

Even though you do not seem to think that it fits the "dictionary" definitions you have found, it does to a large extent according to me.

"Dry": Sister B is not crying, correct? Dry ≒ No tears, no weeping, etc.

"明{あか}るい": While B may not be being cheerful, she is not all that depressed, either, about her father's passing. B does not look like she is left in the dark. So, in that sense, she looks (too) 明るい considering the occasion.　

For the beginners, 「じゃない」 here is being used affirmatively. This has already been explained multiple times here, so I will not talk about it.