Is there doubt that it works or that it is practical? I find it unlikely they went through this rigamarole with a case that was actually just a battery case, but this demo hasn't proven that the product will be widely useful as was claimed.
Well, if all it did was light up the 'charging' indicator without delivering meaningful power then yes, it is believable. But if they actually stand by their original claims then I'd open up that box to see what's in it because with the air density being what it is there is no way you're going to deliver that kind of power between two surfaces of the size shown in the article using ultrasound. You're going to get so much interference between the emissions of the various transducers that you'll end up with a very small fraction of the input power on the receiving side.
