Outdoors Indoors: Cat Crap Drama

Why is it that the cat rewards me for feeding her canned food by leaving the gloppiest shit possible in an astonishingly large pile in the middle of a new white down comforter on our bed? Does she think I'll be impressed? Is she angry? How could that much crap come out of one small cat? I'm just looking for answers. At least I know the culprit. I believe she's been pulling this kind of stunt for years (phantom shitting) and I've blamed it on the dogs.