Anamorphic "mumps" seems a plausible explanation. Note how in every capture, the character is dead centre, or just slightly off-centre. I would be curious as to whether or not the same squishing is present in shots where the actor is in the left or right third of the frame. If not, it's "mumps".
My question is, have you compared any of the shots of Amy Adams or the other "human" co-stars, and did it look this way in theatres? Given that these two characters are Kryptonian, it may have been a conscious choice to make them look "alien". Just a thought.