I kind of enjoy being misinterpreted as a thuggish ice-queen. Gives me a fun persona to play with and nobody needs to know that I cry when puppies die in movies.
Strangers on campus and in bars approach me and say, "Smile, you're a pretty girl!" To which I scowl even more sinisterly.
The distant furrowed brow is probably a result of living deeply inside one's own head, contemplating a myriad of impossible things. It's not anger, but they don't need to know that.