By default, Fallout 4's faces are a little too stiff for many people's liking. Naturally, modders took it upon themselves to fix that.
FancyPants' Immersive Facial Expressions mod obviously does exactly what it says and nothing else. I mean, just look at these facial expressions:
Those are clearly immersive as fuck and not at all piss-your-power-armour terrifying. I, for one, wish we could also graft Pixar characters' gawping mugs onto real human beings. For now I'll just have to make do with seeing these faces in my very good and enjoyable dreams.
If you're a boring person who doesn't believe in pushing the very boundaries of what a face can be, FancyPants says they're also working on a "serious" version of the mod -- presumably something to improve facial expressions in a more realistic way. You know, if you're into that.
Thanks for the heads-up, taltigolt.