What? What does professionalism mean to me?  Some of the things you can think about and include in the essay:  What happened to help me form my impressions? What did I learn about professionalism? What I you do? What did I expect? What was different? What was my reaction?

So What? Why does being professional matter?  Some of the things that you can think about and include in the essay:  What are the consequences and meanings of your experiences? How do your experiences link to your academic, professional and/or personal development?

Now What? How will I continue to develop my professional persona?  Some of the things that you can think about and include in the essay:  What are you going to do as a result of your experiences? What will you do differently? How will you apply what you have learned?