Well, up close bird shot is formidable, the pellets are largely in one group and will cause a rat-hole injury. I've seen it first hand in a shotgun wound to the abdomen at similar range with similar shot size.
My patient had a left flank rat-hole and had pellets in a cone-shaped distribution with the northern-most pellet past the midline at the level of the 7th rib posteriorly. The southern-most pellet was also across the midline at the level of the sacrum.
He lost his spleen, left kidney, several loops of small bowel, had a damaged diaphragm and a haemothorax. He had a damaged pancreas which was clamped, holes in the large bowel, damaged renal artery, colic artery and superior mesenteric artery.
Despite the best efforts of our team at surgery, he died.
Whilst I think it is not a good idea to use bird shot for self defense, I think folks are under-estimating the retarding effect of that iPhone. It is a laminated material with a soft backstop (the man) that "gives."
I certainly believe the man could be dead without the iPhone, and I also believe the phone stopped those pellets as depicted.