A question about Harry potter which has been troubling me?

the reason they can move and talk is because it's magic. I think that perhaps the paintings are just an imprint of who the person was before they died, but not the actual person themselves. It's like a more sophisticated version of the photographs. The 'people' in the photographs capture their real live counterpart's 'essence' and project them back to, but they aren't really that person just a close copy. They can mimic them, but don't have life in them. I hope this makes some since to you and that I didn't confuse you (I'm good at doing that to people)