Paul Anderson focuses intently on audience. That is, he wants you to dictate your writing styles, strategies, methods, processes, etc. predicated on who your reader is going to be. The key is to focus on your audience’s needs in relation to your purposes.
Think of a time when you (or someone you know) had to address a specific audience, whether in writing or speech, and you succeeded admirably. How did you tailor your rhetoric to that particular audience? What adjustments were necessary to inform, persuade, make your text or speech useful, etc.? Why do you believe your writing or speech was successful?
Conversely, think of a time when you (or someone you know) failed admirably at addressing a specific audience. What went wrong? How did you fail to tailor your rhetoric? What adjustments would have been beneficial? Overall, why do you believe your writing or speech failed?