...here:
home.watchprosite.com
And indeed, the HM2 resembles the B&R Grand Minuteur even more than it resembles the B&R Tourbillon.
Personally I doubt that either firm "copied" the other. The lateral struts are a classic "stiffening" solution for a wide flat plate. You'll find similar struts under any domestic table with a single, central leg.
That HM2 Ceramic/RG is a damn fine looking watch.
Cheers
Tony P