Well, it basically works this way: Most people seem to feel that it's perfectly "okay" for them to do something if they like doing it or want to at the moment...because their world revolves around themselves and they are the first priority. They are the star of their own drama. Their reaction to you unexpectedly intruding upon that little drama is usually extreme annoyance or hostility.

Most people can easily tolerate in themselves numerous imperfections that they would loathe and despise if they encountered them in another! ;-)

You were intruding on that young woman's little ego bubble, invading her moment of relaxation, and she reacted in a predictable fashion.   She is, after all, the most important person living in her script....and who the hell are you???? ;-)

If she'd had a really sardonic and wicked sense of humour, she might have responded to your remark "this is a smoke-free area" by blowing a smoke ring casually and replying...

"Not any more...!"