Originally Posted by Coca Cola Duracell Franklin.
I'm not sure how to pintpoint it... he seems to have adopted Daniel Craig's facial expression for this shot. There are so many pictures of him where he looks very Superman-like. Here, he just looks cold and detached and dressed as a Roman general.
That's nothing new though. Superman isn't always this cheerful happy go lucky dude.
Often times he does have a very detached and cold look in his face. If something of great/dire importance is taking place then he usually has that face.