It was if the race track foreground, other craft [middle ground] , and background were all on separate postcards tiered/lined up front to back momentarily.
Then went back to being a cohesive 3D whole.
It lasted maybe a second when it happened.

The more I think what might of been the cause, the more I think it might of been the LCD shutter of the glasses out of sync with the processing of the screen, I can't be sure.
It did it when I moved chairs as well, so maybe the glasses/screen must sync on the basis of distance from each other.

I had given some thought to what I wanted to test out at this demo, as in possible shortfalls of the technology that I've read about elsewhere, so I did give things a good workout

I'm going back on Wednesday for round two, as there was a stuff up with communications ,I'd missed a further message from my mate saying he would have to defer till then