The cool leaf design is indeed interesting. It is close to the previous idea of using an e-ink display.

But it lacks the button shape, so you can see in the video people typing only with 2 fingers, and probably needing to look at it. On another video, in the comments, they say it is more for thing like hospitals where a keyboard easy to clean and disinfect is needed, than for heavy desktop use.

Anyway, if you can make a small translucent overlay with "bumps" on top of the keys, then it becomes usable. The backplane conducting light, with some holes to display the key name, is something that may be done even with small dome-like key ?