Mien
Definition: bearing, demeanor, attitude, or facial expression
Why I Looked It Up
From The Covenant:
By accident, he caught a glimpse of the king’s face and saw that, too, has assumed a solemn mien.
Postscript
Added on
In Monsters, when describing movie critics:
In the screening room, the front-row center seats belonged to the two daily papers, papers given human form in the persons of two white men of unblinking mien.