That surely looks great!
As for design: I think such designs (angular DR bows with a lot of induced working reflex; similar effect is reached largely with DR or Karpowicz's low stack design) are probably very energy efficiënt, because at brace the wood surfaces are minimally strained.
An attempt to explain the presumed principle below:
A conventional straight bow is bent to a shallow C at brace, and is already strained a certain amount. This stored bracing energy is not available to the arrow but strains the wood nevertheless. This means that for a 22" power stroke and 6" brace height, you need to strain the wood for a 28" draw.
Having a much lower brace height eases this a bit, but is uncomfortable to shoot (you increase the length of the power stroke) due to string slap and very different arrow paradox.
What if you could have a 22" power stroke, have a regular brace height and still strain the wood only for a 22" draw?
Say you could keep a zero distance between much of the limbs and the string at brace, and still have a normal brace height by putting the handle (and only the handle) 5" above the rest of the bow? Enter the angular DR or other low-stack DR designs.
There, the surface wood is minimally strained at brace, as the limbs hardly bend beyond what the wood used to be as a stave (or slats of wood, in this case). Bracing energy comes from recurved limbs being forced to a more straight position, compressing the limb longitudinally. You can get very high string tension at brace this way.
Apart from Marc St Louis's example, have a look at redhawk's blog as well
https://redhawk55.wordpress.com/ or Lukasz Nawalny's DR angular bows
http://www.primitivearcher.com/smf/index.php?topic=24280.0Hence, for a 22" power stroke (in a 28" draw), you strain the belly and back wood only for (a tad more than) a 22" draw. Which means you need less wood (less mass), you have less hysteresis (as you strain the wood less), and so on. All of which is advantageous in flight shooting, and in general in bow efficiency.
As said, you do need the recurving to get a high string tension at brace, but this recurving is induced with heath (steam or dry heat), and allows you to store energy internally in the limbs rather than by straining the surfaces (as for perry reflex).
Overdoing the recurving in such bows (like in the hickman extreme recurve
https://www.flickr.com/photos/farflinger/5177069236/in/album-72157625386947492/) reduces efficiency again, as during the limb return the length of the lever reduces again (it carries dead weight at the tips during much of the draw or limb return, increasing inertia, despite storing more energy). See
http://paleoplanet69529.yuku.com/topic/56228/Interesting-novel-high-energy-storage-recurve-design#.VW9-KPntlBcYou need immediate lift-off of the string from the recurves to have maximum efficiency.
In the bow you show here (just like in the other examples mentioned) all ingredients come together for a very fast bow.
