Well, my idea was an image like a comic strip, but all concentrated to one square, which would be at one end of the banner, while the rest of it has the 4 Dimensions text.
For exampole; the scene is the Timetraveller facing the Dragon - (or probably just the dragon's head, due to the difference in sixe) - and then just the text in the 'talk blurb' changes.
We have to keep it as simply as possible since it's a banner.
I'll see if I can whip up an example of how I think it should look and post it here later today.