Bug regrading certain personalities and emotes. Easy way to fix it is to equip and unequip a personality. I know for fact the assassin personality, when toggled off and on, will wipe odd faces.
I noticed on PC after the last dlc. Zoning, hiding helm, relogging would make it right again. It seemed using crafting tables made me really really angry.
A few of us have had weird expressions happen without having any personalities active at the time as well, or without using emotes (currently if you use an emote your expression gets stuck like that). There is a certain angry face and shocked expression that are related to using a blacksmithing station or mounting up though if you're getting either of these:
Shocked face from mounting:
Angry face from blacksmithing (not my image):
PC NA & EU || Mammoth Guilds - Victory or Valhalla || Altmer sorcerer main
"Wood Elves aren't made of wood. Sea Elves aren't made of water. M'aiq still wonders about High Elves."