First off its venting back into the inlet system which although the original design (albeit slightly different to this) is only good for saving kittens and baby foxes, not for keeping the engine breathing clean fresh air.
I'd personally be using both breather outlets on the rocker but i don't know if this will have massive detrimental effects by just using the one.

I'm more interested in that inlet tbh. Looks a very strange design? have you get any better pics?