This may get me blasted out of the sky here, but I am confident that Zod's suit in this image is just as physical as Jor-El's. I don't think it is CGI, because Faora's is also not in the behind-the-scenes images we have seen. Why should Zod's be CGI?
The images we saw of Shannon in mo-cap are for something else we have NOT seen yet, and won't until the movie... the mo-cap was not for the suit he wears like Jor-El and Faora. It is for something much bigger, as evidenced by two things; one, there was a ball on a stick mounted on his head, about a foot higher, for visual reference for the computer and also his fellow actors. And he said that what he was supposed to be wearing in the mo-cap suit as too big for him to wear in real life. The armor is not. HENCE: I believe he will be wearing a Kryptonian Battle Suit at some point.
If someone else has put forth this theory before me, I apologize, I have not read it. But time will prove me out, I think.