"What does a philosopher do?" Some form of that question is bound to get put to those of us unfortunate enough to have a degree in this area. A professor of mine once mused in class about how he'd catch himself staring out a window, doing his work. And weirdly the work of being a philosopher sometimes hits you over a cup of coffee or in the shower or looking in the refrigerator.
Ultimately philosophy is a field that you develop a speciality in over time. So I can say that a lot of my studies in philosophy were in philosophy of language and philosophy of perception. Sometimes we also talk about an interest in philosophy. My interests are in aesthetic particularly film, but also philosophy of language and to a lesser degree metaphysics. That's a pretty broad but a very standard answer to the question "what are your interests in philosophy?"
But maybe the measurement of what a person is doing in philosophy is a matter of where their major contribution to the field is. And that's something which develops almost by accident. You have your interests and your training and eventually some area falls in your lap that needs to be expanded upon. But eventually you have years of work on one thing and maybe one day a novel theory in the field. Usually some uninteresting distinction to well tread ground.
If I can say I've made any sort of contribution to philosophy, it'd have to be in axiology--the study of values. Basically the upshot of my undergraduate work has been a fairly uncontroversial but perhaps unexplored distinction around the ethical value of art and art-like works and the aesthetic value of art and art-like work. My contribution developed quite by accident and goes all the way back to an interest I developed in high school with propaganda films and how they are effective.
I'm going to post that developmental work so a reader can see how specialization develops at the very early stages of a philosophical career.