The demo they do on stage is weird because the overly exaggerated expressions she was making looked just as unnatural on her as it did on her Metahuman double. What's impressive is how quickly it went from raw input to a usable, fully customizable asset. That to me is absolutely its biggest selling point.

I think a far better representation is the second one for Hellblade 2.

The stage demo literally produced something that has more accurate capture than a number of games shipping today in real time using a phone as the capture device with no tweaking of animation by hand. My guess is the exaggerated facial animations are easier to capture using a phone, but regardless that's insane. The goal of this demo isn't that it's flawless, it's that it's quick for a quality capture and you can use consumer hardware.

It looked very off, but in their defense the model did some really unnatural facial expressions.

I don't know that "looks natural" was the point of this demo. As someone said elsewhere, they produced a facial capture animation that was 85% accurate to what the actress did in about 3 minutes, using an iphone. That's pretty impressive.