It does look cool, but:
It doesn't look as if you can carry all that much in it. For many loads, you'd be far better off with two or four panniers (unless you're already carrying four panniers), or a flat-bed, two-wheeled trailer. (After all, aerodynamic efficiency is unlikely to be an important factor once you're hauling a trailer - unless it's with a
Cab Bike, which this company also makes... although even that's hardly the slipperiest velomobile...)
The wheel is so small that the load is going to get seriously rattled and shaken, and it probably won't roll very smoothly (this is one reason why bikes usually have much bigger wheels than this). Two larger wheels, with nice tyres, would probably roll much better and make hauling it easier.
One-wheeled trailers can be a bit sketchy if carrying any serious load. And if it's not a heavy load, why not put it on the bike?
I guess it's eye-catching, but then again it's so small and low you'd pretty much have to trip over it to notice it in an urban environment. Perhaps you could deliver eggs in it, but not many, and they'd definitely be pre-scrambled on arrival.