The pics are kinda blurry so its hard to tell exactly what all is "out of proportion"...
But from what I can see...there are 2 bulges, one at the base and one about the middle.
It fired slightly out of battery...all Glock pistols can do this, but they shouldn't do it for no reason. (I expect the same is true for any striker fired pistol)
Causes...ammo loaded too long, brass way too long, VERY dirty chamber, etc...
It might have been an overloaded round, but I don't think thats it...that brass looks like it was fired at an angle. (or maybe its just the way the light is hitting it)