A selfish approach would mean that you took only into account your own needs in making a presentation and did not assess the audience or its needs. For example, if you had to present a great deal of technical material to an audience, technical material that you were comfortable with, but that the audience was not comfortable with, you would make no adjustments in your presentation to help your audience with its lack of knowledge. If I had to make a presentation on literary devices, a subject I am quite familiar with, I might go on and on about metaphors and similes without explaining to my audience what they were. It would be my need to present or even to show off my knowledge, rather than my audience's need to learn, that would be the focus of my preparation and presentation. Would my audience learn anything from my selfish approach? Not at all!
An audience-centered approach is always best. To the degree possible, you want to know who your audience is, what their level of comfort and knowledge is concerning the topic at hand, what they might find interesting about the topic, and how to involve them in the presentation. A selfish approach is never to be recommended.