How do you respond when told 'you look bored/annoyed/confused/lost' etc.?

I find it disconcerting to be told I look like I'm feeling/thinking a certain way, whether or not it's true!

Sometimes the person is correct about how I feel, and sometimes they're wrong and I'm just spaced out or thinking about something else. Either way, it's awkward! Not only do I have whatever was bothering me, but now I have the problem of my face doing things I didn't ask it to, and having to explain myself 😖

(It's usually in a work situation, so I need to be polite when responding!)

How do you handle these comments?