Really depend of the situation.
I mean, I always carry with me a sketchbook and can start to draw in it whenever I feel like to.
Though, I don't mind if people look 'cause I know that they are not paying attention anyway.
But, if someone is actually trying to "look" what I am doing, I might stop and ask what they want. x,D
Besides that, I'm used to it, at school my art teachers was always doing this and was looking at what I was drawing all the time.
I also don't mind about streaming live, but I am not comfortable when I do sketches 'cause I fear that, when I will do an errors or simply erase all my drawing, people will judge me or laught at me. x,D
Though, I'm still okay about it, especially when I do free sketches streams, everyone can do errors~
BUT, if I am ever sketching a, you know, hmmmmm... "picture that you don't usually show in public", well here, it's a big NO. Nobody can look. C,: