What the hell is a
throw pillow? Is it a pillow you throw out? Or do you throw it at someone. I would call that a pillow fight.
Maybe it's a pillow that throws a good punch. The Ali/Frazier Collection. Knocks you out for the night.
In any event, it's a pillow that spends its life on the sofa, so who cares how it got there? "Ya, that pillow I threw onto the sofa 12 years ago. It hasn't moved since."
"And this other pillow?"
"That one was gently placed there. Don't use it. It's delicate."