Why can anxious and self guarded body language come off as arrogant?

I just think it's kinda interesting, because that type of anxiety usually comes from feeling lesser than everyone and desperate to avoid conflict or negative reactions, yet it seems to invite the type of reactions they're terrified of.

But that type of boby language is a natural response for self protection,
Not to attack, not to ward off, but to be unnoticed and hide... So I'm wondering, why does that have the universal potential to communicate otherwise?