One way I would describe openness is: genuine (non-antagonizing) curiosity. That is, not weaponizing curiosity as a "just asking questions" antagonistic rhetorical strategy.

It seems easy to point to examples of "closedness" once we've encountered instances of them. By contrast, openness is weirdly hard to describe without referencing closedness.

(sorry. philosophy is just where my head goes these days)

1) openness to sharing knowledge [whilst avoiding obnoxious mansplaining and acronym-everything, sharing and asking in turn, spirit of co-learning - we all can learn from each other, of course];