I couldn't find anything about this year's show, but I did find this article about the set designer of the 2014 show that used VER equipment. I would guess that it is a large projection screen with one of the very high end projectors driven by a computer.
A few of the professional model train layout builders have theatrical set design background and training. That led me to study a few books on theater and tv set design for concepts and techniques to apply to layout design.
So, one may be able to create a backdrop Masonite board painted with screen paint and use a few affordable projectors hung on the ceiling to create an effect similar to the show's.
However, you will discover that any of the lighting and effects generators used in theater are quite expensive.
I thank Pink Floyd for setting the stage (pun intended) for technology in theatrical shows. The Eclipse Tour 1972
