There's a mismatch with the number overlaid on the portrait and its twin on the right-hand side. I acknowledge that level of scrutiny for online verification probably isn't scalable, but c'mon, the security features are there for a reason…
Are you talking about the main image of the California license? He says further down in the post that he didn't test that one as the website doesn't accept US IDs. He used a passport from the UK to verify, photo is in the first reply though I think you have to log in to see if.