My goodness, my goodness. What an art lesson.
It is very obvious that when you move the 3 and Ida Mae closer together it takes the eye away from the ends of the car, as you tend not to look at those parts. As much of an interest I have had in art, I never thought of applying that to a model.
There are a number of design principles in paintings that can be used to lead the eye around and to fool the eye. Such as a toned down object at the edge to keep the eye from running off the paper or canvas. Or the use of a pathway around it to lead the eye back to the center of interest. I see a similar idea here.
Just as an added thought, many times on my models I will add what artists call " a little entertainment " which is really " nothing " but seems like " something. " I usually do it with painting a dot or a dash, or a small square shape. Usually something in the engine room that might look like a nut, rivet, wire, or fixture.
Hope this adds a little something to the discussion, here, David without meaning to steal your thread.