This is the counter to the previous play which wants to throw the player on the ground along with the horse. It is a simple thing to know that when the scholar throws his arm over the neck of the horse to take the bridle, immediately the player throws his arm around the scholars neck, and forces him to drop it, as you see drawn here.
Here, your opponent has reached across your horses head, and is trying to twist both it and you to the ground. To get a good grip on your horses bridle, they need to extend themselves quite a bit. This provides your opportunity for a counter.
In order to throw the horse, your opponent is trying to twist its head not just axially, but also in an arc out to your left, and back across the horses withers.
Form your right arm into a smooth curve. You want the points from your fingertips, wrist, elbow, right shoulder, left shoulder to make the arc of a circle. There is the sensation of flaring out the elbow and leading with the top of the thumb.
Keeping your core attached to the saddle, extend you arm, curving it around your opponents neck, as shown in the picture. Slide your arm along the neck. You are aiming to get their head resting in the hollow of your right shoulder. The twist your opponent has given to your horse will cause it to turn slightly to the left. If your opponent does not let go and immediately try to regain their balance, they will be peeled from the saddle, falling backwards by the front right foot of your horse.
The distance of your opponent, and the fact that your hips are bound to the horse means that you will not be able to perform this technique as smoothly as it appears in other plays. Despite this, you can see what is conceptually the same throw in the following plays.