[HELP]Regarding pizza dough - Why is it balled up this way as opposed to the "conventional way?" Also to make a thinner crust, why can't oil be added before the toppings are added?

I'm watching this amazing video ow how to make pizza dough. Notice how the chef is making the pizza balls like this as opposed to the way we make Play-Dough balls? Why is there a difference?

Also, notice how this chef is stretching out the dough this way? Could the dough's thinness be achieved by adding oil at this stage to the dough's top surface, and then making it thinner?

bon appetit