Cas has a hard expression to read, as he is an angel in a vessel, and he has not had much experience being human "I'm Castiel, Angel of the Lord, who are you?" He asks, seeming to come off a bit rude and cold, but that is only because he has no idea how to speak to humans in a proper and polite way

Castiel's vessel that he has taken is a shorter man with nice blue eyes and an innocent-looking face