This was a bad demonstration of relativistic effects. All it really does is demonstrate the Doppler effect, and it does that poorly. People are evidently not warm, because they do not glow when infrared light becomes visible. Chimneys do, but so do shadows under roofs.
The huge mushrooms emit what, gamma rays? They emit light that is visible even when enormously red-shifted.
There is no Sun or sky. No campfires. No warm machinery. No radios. No flowers with UV patterns. Nothing familiar that will illustrate something interesting about the Doppler shift and the world of invisible light.
It's a nifty idea, but finish it before releasing it.