They may be for real world usage, you dont want rocks or sticks getting inside
Absolutely, my point was that if you can remove them for this sort of demo, then if they get damaged by a pothole then it's probably easy to replace them.
The demo tires shown here don't have "removable" sidewalls. They were manufactured without them. The production tires will be one piece, like normal tires.
Sidewalls are critical for NVH at higher speeds, as well as fuel economy. But a demo of a tire on a car going 55 mph doesn't make sense, so they are able to remove the sidewalls for these stationary photoshoots and low speed rolling tests.