"Oh no, Dumbledore, I am too tired tonight."
Something about Phineas's voice was familiar to Harry, where had he heard it before? But before he could think, the portraits on the surrounding walls broke into a storm of protest.
"Insubordination, sir!" roared a corpulent, red-nosed, wizard, brandishing his fists. "Dereliction of duty!"
"We are honor-bond to give service to the present Headmaster of Hogwarts!" cried a frail-looking old wizard whom Harry recognized as Dumbledore's predecessor, Armando Dippet. "Shame on you, Phineas!" (22.61-63)
So, we have a question about the portraits: obviously, Phineas Nigellus still has a very strong sense of himself. Even though all of the portraits of former Hogwarts Headmasters are supposed to help the current Head, he rebels and drags his feet rather than carrying a message as requested. Yet, we are also told that the portraits are less than fully realized ghosts. J.K. Rowling explains:
[The portraits] are all of dead people; they are not as fully realised as ghosts, as you have probably noticed. The place where you see them really talk is in Dumbledore’s office, primarily; the idea is that the previous headmasters and headmistresses leave behind a faint imprint of themselves. They leave their aura, almost, in the office and they can give some counsel to the present occupant, but it is not like being a ghost. They repeat catchphrases, almost. The portrait of Sirius’ mother is not a very 3D personality; she is not very fully realised. She repeats catchphrases that she had when she was alive. (source)
So, if they are just impressions of living people, how is it that Phineas Nigellus seems like such a prickly, well-rounded character – a character who is capable of feeling sorrow and confusion at the end of the novel, when he discovers that his great-great-grandson and the last of the Black family has died? Can you make a distinction between the portraits and the ghosts? What makes a portrait's character different from a living character in the novel?