In the video, there is the phone-to-screen projection mockup, which is smooth and, imo absolutely fake, and cca one second where a developer is dragging the window from LCD to e-ink screen, and it shows the real frame rate, about 3–5 fps.
Even at 3fps, the process of repainting an eink/epaper display is unpleasant to look at - though at a microscopic level it's quite beautiful: https://www.youtube.com/watch?v=1qIHCUWAgh4
Interesting, thanks. Unfortunately the combination of super annoying background sound and the totally weird voiceover drove me to close the tab about halfway through.