Looks pretty neat...tiny 300dpi rewritable epaper display that needs no power to retain the image. Sort of high tech etch-a-sketch.

I think they are overstating the security aspect though. You wouldn't​ need to recreate the tech to mimic one of these. Actual paper behind clear plastic would probably look similar if you experimented with paper color, print color, some kind of bezel effect and the plastic overlay.