Like the description says this is The Good Omoplata.
We have all been taught the traditional way where you sit up with the near arm and try to hug over the hips. As you can see in this video it is literally the complete opposite. This is a good thing for a number of reasons.
The first reason is you can disengage your hips from your opponent fairly easily. By moving your hips away it buts a LOT more pressure on the back of your opponents shoulder and increases domination.
The second reason this is a great idea is because it takes about half of the abdominal strength/endurance. This may not seem like a big deal but in the 7th minute of a match this can be the difference between getting the submission or not.
The third reason reason this is a good idea is it becomes almost impossible for your opponent to use the traditional hop over you body. This becomes impossible because you are moving up from that side and not possible to beat you to a side if you are starting there.
The last reason, and arguably the best reason, is that it gives you the ability to chalk your opponents hips and move your body away. This is the most powerful way I have ever seen to break someone down. This will actually angle your opponents chest away from you and multiple the force of the submission.