It's a 1/2 cheek with a ring. I've never seen them used together, or as a combination bit. I'm familiar with a 1/2 cheek as a driving bit. I'm sure it's being used to keep control on a very strong racehorse. Certainly that chain and the noseband being used to keep the horse's mouth closed, indicates this, at least to me.
That's what is commonly called a 'ring bit' in the racing world. Very very common, I always liked it when I took a horse to the races and he was wearing one in the bird cage......one can very discreetly slide their fingers over that ring and get control of a horse that's going a little maniacal while trying to drag its handler into the bushes (blush....yes that's happened to me!) or rush by the blaring brass band!!! That's not the primary purpose of the bit, but it's handy!
I was told the chain on top was to release endorphins from those pressure points to calm the horse down or something. I don't know that for sure though. You see similar things in racehorse's mouths when they are being led too.
I don't have a problem with ring bits. We use them frequently at the track. The only time I ever see the chain directly on the gums is when it's a truly difficult horse. My great-great-uncle wraps his chains and doesn't put it on their gums though, he puts it over their noses.