As a hunter who has been shooting shotguns since he was eight, let me point out a couple of things:
The butt of the shotgun is too high. It's supposed to be tucked into your shoulder.
The cheek "weld" is too tight.
Repeated shooting like that would cause major bruising on the cheek and shoulder.
His hand is positioned wrong on the stock. It's almost on the bottom barrel. The balance is off (IMO).
And one choke means probably one shell.
Also, no recoil. His shoulder would be further back with the "kick" of the gun.
His stance is horrible.
Not leaning foward enough.
To me, the entire right arm looks PSed.
This is obviously someone who as never shot before and has never been coached by someone knowledgable.
This is embarrassing.