From the prop and the cowling, I think the pic is of the Thielert powered plane.
I am thinking that there will be a couple 550 powered versions as well, but Diamond also uses Lycoming. My bet is the continental though. Diamond has got to hate spending money at Textron/Cessna.
I would say that the reasons Cirrus outsells Diamond are:
BRS - like it or not, it sells airplanes.
Marketing - Cirrus has them whipped
Drive - Cirrus went whole hog to be number one. They mortgaged everything and bet on high volume. Diamond OTOH, is private, and the owner really doesn’t seem to care about competing over who sells more. He does want to avoid losing lots of money.
Sales Model - Diamond’s distributors are a mixed bag. I think Cirrus may have the better idea. Interestingly, Mooney has a mix of the two and can’t seem to decide which is better.
I would say that Cirrus does not outsell Diamond because they make a “better” plane. They don’t. They make a plane that is more desirable to the people who buy most of the new planes. Cessna certainly does not have a better plane, and they outsell Diamond.