Swell is a hollow grown copper container that’s been shot with a .45 caliber slug, turning it into a serviceable flower vase via the exit wound. It’s “an object formed for its deconstruction in the hope of eliciting new beauty.”
Guess this is similar to the statement Rose was trying to make in posting a photo of her four-year-old daughter wearing an ammo belt [Video]. Some of these things are go over a simple-minded old paratrooper's head.
As to the shape ... let's not go there.
Speaking of Rose, see the continuation (if interested)