It helps to realize that most people are fairly self-involved...meaning, people mostly are thinking about their own needs and feelings. Most of the time, it is not about "you".
Can you give some examples, though? I don't know, I am a pretty closed off person, and I am not going to lie, my normal face is kindof a "bitchface". I will catch myself in the mirror and by like, "yikes! I am in a great mood, too!" I don't like people to get too close and I would say my body language is closed off and unapproachable. But I would hate it if someone were to take it as a personal attack. Because it's not that I hate people or think bad thoughts about them, but I also am not super open to being touched or having people in my personal space, and lots of people, strangers even, like to cross that boundary so I do present myself a bit as "back off, I am busy, talk to someone else...or at least, dear God, do not touch me!" LOL.