The brilliance of your message is only part of what an audience will focus on during your presentation. The other part is you: the visual package you present. The audience views your presentation as a whole. So what they see—as well as what they hear—contributes significantly to how engaged they are and how they evaluate the time spent with you.
When I deliver the ATD Presentation Skills Certificate Program, we talk about how your audience interprets some of the things they might see