Generator is not a magnetic potential to electricity converter. It is a magnetic flux into electricity converter.
You can create static magnetic potential by running electricity trough a wire (coil). Naturally a reverse device would be interesting.
Regarding this demo, how was the device advertised? I did not get any clear definition from the video.
If it would be promoted as ZPE then I would say it is misleading. But as far as I got they just demo the device, without defining what it is.
