It's conceivable that this somewhat works. Even if half the pictures are the wrong random white guy.

The more interesting question is what they do with the information. Does it add that much to the records they already have from your cellphone and KYC wifi use? Maybe, if you were seen talking to someone.

But I also suspect much of this is theatre. The guy at customs probably enjoys showing off his fancy tools. And the CCP likes you to see them, so that on your next visit you behave.

Anyway, may we live in interesting times... 

 The perpetrators were Chinese (men and women). There was 20+ minutes of extremely clear CCTV imaging of their faces and identifying features from multiple angles. 

If the CCP “face scanning tech” is as sophisticated as they want to rest of the world to believe- they could have located the individuals in a matter of minutes. 

I suspect it is not. Still scary knowing that it will be soon (or is now).