If you are the person creating a panel, you need to select people who either have something in common or represent different perspectives on the same topic. It takes more work and extra planning to make this type of presentation work. You have to research the panelists and coach them in how to make the panel successful and then you need a moderator.
At last year's Green Wine Summit, I had the pleasure of moderating a panel on green packaging.The panel included two representatives from a glass manufacturer, a passionate cork enthusiast, representatives from a winery that had a wine box, and a restaurant who was selling their wine. I asked them to each provide me with their three main points and submit photos that represented their perspective. When they responded, I had enough information to create some dialogue between the panelists.
I did however, get the photo below from the cork board representative.
While thankfully none of the other panelists had comparable images to share, they were able to make their points using their own graphics.