Translation
You take me from behind to throw me to the ground and I turn like this. If I dont throw you to the ground, you will have gotten a good deal. This play is a finishing move, but it must be done quickly so that the counter will fail.
Interpretation
There are a number of ways you can arrive at this position. Fiore gives us the context that you have been grabbed from behind. While this certainly works, it is not limited to such a scenario. As long as your hands are free and you are at extremely close range, you can use this play.
The 9th scholar of the Sword in One Hand uses the same entering throw, starting from wide play and then rapidly closing in on the opponent from directly in front. The 6th scholar of Sword in Armour also makes a very similar throw after closing from the front.
Swing your front foot around behind your opponent. You want it to be between their feet. As you do so, extend your front arm across your opponents chest and throat with the hand over their shoulder as shown.
Flare your knees and drop your weight down so low that your thighs are parallel to the floor. This gives you an extremely solid base. As you drop your weight, extend your arm through your opponents space. Dont twist yourself, but rather push straight along the line of your legs.
You should arrive in Posta Longa, although your legs will be in a deeper stance than usual. Effectively, you are creating an obstacle with your thigh, and then pushing your opponent over it. Aikido practitioners will recognise this technique as kokyu nage.