This is like asking if the essence of person is the blood and guts that keeps them alive, or the skin and bones that holds the blood and guts together and protects it.
Surely the
essence of person is "thought", "the conscious" or whatever you want to call it? The neurological impulses that make us live, act and survive is the essence of person. The blood, guts, skin and bone is just the physical vessel which holds it together.
I see it more like a house is a building with bricks, concrete, etc., but a home has something more to it.
So the Kool Aid man is the full package. He is the liquid and the glass. But what makes the essence of the Kool Aid man is different. What is the analogous thing of neurological impulses and waves for the Kool Aid man? The swishing of liquid? The technology that makes the pixels on the screen move?
I went a bit too deep and meta, didn't I?