I flew a couple of weeks ago and noticed that, too. Much more detailed inspection. Also, the wait to get the patdown was very long and the ones doing the patdown are the biggest, meanest bruisers they have on staff. I believe they are trying to 'incentivise' us to go through the machine and not inconvenience them with the opt-out.
Funny, when you fly internationally you rarely see one of those things.
I went to Panama in March. They had standard, normal security.
When I got to the gate to get back on the plane to get to the United States--it was like something out of a bad dystopian movie. You had to go through our "special" security. Big Sis was playing on a big screen spewing out propaganda, men in black, signs. They were going through everyone's bags with menacing looks on their faces...I was embarrassed and sick seeing it.