what

let's see; what have we got here

Nothing

which (of three or more) / which one /

spirit; mind; heart / mood; humor / air; atmosphere

a sign

(idiomatic) to care about something, to pay undue attention to something, to mind something which is a negative nuance, to worry about something

plain negative imperative form of 気にする: never mind!; don't worry about it.

to have an interest in something or somebody, to be inclined towards doing something

(idiomatic) to cause concern, to be worrisome, to be on one's mind / to be interested, to be curious