That explains how to screencap a real functioning app and composite it on top of real hardware that's otherwise running exactly the same thing. That is not what is going on here.
According to TNW "Plastc didn’t have a prototype for me to see during a meeting" and what they showed was a UI inside of a fake card.
I think the parent's comment still has a valid point. In the app demo it is more a presentation of something that we are presented how it is, the app. When we will download the app we will get what we see in the video, it is pretty and gives a realistic idea of the functionality makes the app pretty, but the app is still the same. On the other hand, the video in op's website is simply a fake as in it's not a real representation of anything concrete. It's a promise, a nice one, but still not concrete or real and we all know that the end product might end up highly different from the promise.
But it also makes it tempting to make the interface appear much better than it actually is. If you're faking it to "make it legible," heck, why not just make it looks really nice as well? Companies like Apple have gotten in trouble for faking their interfaces in advertisements.
