I found some more info on that "helmet." It is called the "stratosphere" and it is a Rudy Project product. But it is classified as a "cap" because it does not offer the protection required here in the USA. I found it on their web page in the "international" section under helmets.
It looks like it would be a little bit more aero than the typical helmets we here use. I know when I ride I can see in my shadow that my jersey, just behind my head and between my shoulder blades, is flapping in the wind. It seems that the extension on the back of the stratosphere would eliminate this tiny bit of turbulence/resistance. Who knows, maybe this is more resistance than it appears.
I would like to try one of these helmets out but the web page says that they cannot sell them in the USA. Guess I am out of luck.