Using imaginary or abstract visual aids

Even imaginary visual aids can be powerful in a speech. You always can talk about and point to things that aren’t there. On page 180 of his 1996 book Plain English at Work Edward P. Bailey gave three examples. Two are:

“One person was showing the distance someone could broad jump. So she made the stage an imaginary place for the event, started at one edge, and walked the distance for the high school record. She talked about that awhile, then moved a little farther to show the collegiate record. And so on.

....Another made the stage an airport, showing which directions the planes would take off and land, where the gates were, and where the control tower was. She then used this to illustrate the various traffic patterns the planes would fly, depending on the direction the wind was blowing.”  

An airport also could be shown abstractly on the stage using rope and colored yarns to mark runways and taxiways, and sheets of paper to indicate the control tower and terminal. Your audience will imagine the details.