Those are bark grafts. You slip the bark when the sap gets flowing, cut a wedge into your scion, and then slide it in and make sure you have good cambium contact. Usually they graft 2 or 3 pieces on and keep the most vigorous one, but maybe they’re going for something different there? All of the apple and pear grafts I’ve done are whip and tongue on single rootstocks.
There’s lots of different ways to graft, but in most cases you want the sap flowing in your rootstock and then you graft a dormant scion onto that. That way the rootstock is ready to go and pushes the growth through the scion wood.
I field grafted a few pawpaws this year, but they’re a little finicky. They prefer consistent temps around 80° to graft and callous off whereas apples are early spring. Middle pic is actually a cleft graft since it was a little too low to get a good whip and tongue on there.