It is an imprecise definition, but to take away more general advice, perhaps this is:

1) Be the best person you can be (and seek to find for yourself what that means, by noticing the people you admire in your life who you judge to be good people)

2) Don't pretend to be something you are not just to find a relationship or impress someone. If you followed 1), then you will be both attractive and acting in a way you feel good about, instead of being an asshole.

This generally agrees with your comment, while adding a bit with point 2) about how authenticity can be defined as "don't be something you are not, unless you genuinely want to change for yourself and yourself only."