It is tradition for witches and wizards of note to sit for portraits, so their legacy can be retained long after they’ve passed, hence why Hogwarts is covered in the frames of countless figures from wizarding history. But while each painting has its own unique personality true to their sitters’ real lives, some are more textured than others. While Sir Cadogan will jovially challenge anyone to a duel who walks past him, true to his days as a knight, others, such as Albus Dumbledore’s portrait, seems to emulate the sage headmaster’s famous intelligence perfectly.
According to J.K. Rowling, the more powerful you are, the more ‘real’ your portrait can be, and if you sit down with your portrait and spend more time with it, the more accurate a portrayal of yourself it will hold. This is why Albus Dumbledore’s portrait is so lifelike, while his Chocolate Frog card, which also holds his image, is more of a fleeting snapshot – which is still sentient in a smaller way.
Hence why Dumbledore’s portrait feels so realIn Cursed Child, Dumbledore’s portrait is able to serve true emotion when talking with Harry, and is even self-aware of the fact he is just a portrait, poetically dubbing himself, ‘paint and memory’. Despite this, Harry and Dumbledore’s portrait are able to he a frank discussion just as deep as they used to during Harry’s youth, with Dumbledore even admitting to Harry he loved him. In the play, McGonagall briskly tells Harry that the portrait is still just ‘a memoir’, but it seems pretty convincing to us. You’d never get that sort of heart-to-heart with the Fat Lady.
But portraits and ghosts are still quite different