the prevalence of surgical masks in China might also be a challenge

Sunglasses and hats too!

No, Apple has explicitly stated that hair style, glasses, hats, etc have no impact on the face detection.

so does it mean that to unlock the phone I just have to knock you out and put some sunglasses on you?

How would that be any different than knocking someone out and using their finger for the Touch ID?

Well for one thing it'd be a hell of a lot more work to cut off a guy's head vs. just his thumbs (if you want to unlock again later).

exactly the same, which means FaceID is not that much more secure unless as part of the authentication process you have to smile on cue or something

Apple has said it will work with glasses and hats

But not sunglasses.

What about twins? Does touch ID even work with twins?

No. They even brought up Spock and Evil Goatee Spock to mention that twins defeat it.

(I say "defeat". Schiller just said the chances of a false positive were higher with twins than the 1/1,000,000 base rate [compared with his claim of 1/50,000 for TouchID])

This was explicitly brought up by the presenter (though through the premise of an "evil twin" and a photo of Spock from Mirror, Mirror) and they said you should consider a password.

that sounds like a lot of inconvenience

I am a twin and me and my brother managed to fool windows hello. I plan on going to an Apple Store with my brother to see if FaceID can't be fooled.

Oh, this is very interesting! Please keep us posted!

Twins shouldn't be a problem. Even the ghetto facial recognition implementation in the AliPay app (a Chinese PayPal clone) can tell twins apart. Surely Apple can do an even better job.

Can still use a passcode

The passcode doesn't let you get rid of the hideous screen cut-out, which seems to be primarily for this lock.

You would still need it for the normal front facing camera (look at the Essential Phone).

The cut-out also has the speaker, front facing camera, and ambient light sensor, or would you go without those as well?

Infrared should pass through thin layers of clothing with ease.

it's all a plot to make women remove their scarves