Actually no, they look at your face and your ID, make sure the information matches, and move you along. No secondary inspection, no difference except you didn't get scanned with facial recognition. It's the same process as before facial recognition was implemented.
Why even write that comment?
I've been in and out of DFW, BOS, and JFK since these facial recognition scanners went in and I can tell you with a great deal of confidence that there's no additional wait time, or queue, or anything else if you opt out. There's a TSA agent right next to the scanner who collects your ID whether you get scanned or not. That's the same person who otherwise just checks it if you opt out. What are you even on about? Maybe its different at some airports, but I've been opting out every time I fly and it's no big deal.