this is a solid question
Thinking about it, how would this affect comics and illustrated books? Does it only apply to paintings? What about sculptures?
How is their personality determined? They remember things and appear to have their own opinions, so are they technically people? Or maybe they’re just echoes of the artist whose thoughts and opinions are projected onto the painted figure? Perhaps the subject of the paitning uses something similar to a pensieve to implant some of their personality into the painting?
What if the painter only paints half of the figure, does the other half just magically appear, or does the other side simply not exist? Maybe the figure is animated while they’re painting it, so they can turn it around and paint the other side, like a 3D model? What happens if a figure from a painting travels to another portrait but their original portrait is destroyed beyond repair?
Also, I think I remember Ron being confused at the idea of art not moving, so either wizard paintings and art just naturally animate or it’s just the done thing for wizards to cast a spell after the image is complete, otherwise it’s not really art? Like, I can imagine that they have a very strict view on what art is and isn’t, because the wizarding world tends to ignore what goes on in the muggle world and are also quite backwards in terms of traditions, fashion and ideas, so I reckon their idea of what art is meant to be hasn’t progressed much as they haven’t had a cultural revolution like we did after the invention and popularity of the camera? Like I bet there are spells which accurately paint people or scenes quickly, but it could look better or worse depending on the skill of the wizard, so perhaps the camera wasn’t that revolutionary to them because they already had a way of accurately capturing portraits, it’s just the camera meant less effort?
SO MANY QUESTIONS
The paintings we see in the series are generally of people who actually lived, and their personality matches the real person, which is probably part of the enchantment.
We know it doesn’t just apply to paintings, as photos do it as well. There’s a potion which they use in developing the photos, which (I would guess) is probably mixed in with the paint for portraits. Photos, like portraits, behave like the person they’re of.
There’s also evidence in the series of some places/roles being enchanted so that a portrait immediately appears, but it’s likely that other paintings are painted from scratch, hence why Filch can repaint the Fat Lady’s portrait, fixing the damage done by Sirius Black.
In the films, we see a moving doodle which Draco drew of Harry, which behaves as Draco willed it to while drawing. I would imagine that, depending on the wizard or witch’s ability with this particular area of magic, this type of enchantment could affect comics or any other image of living or moving things. That would be the wizard’s choice, but I’ve always just assumed that wizard comics moved, though other print images we see elsewhere don’t talk, and a talking comic when you’re trying to read the article above would just be a nuisance really.
As for the idea of abstract or cubist art styles moving and speaking, we can presume that any could be made to move but only paintings that are of/are intended to be of human beings, merpeople, centaurs, or any other creature capable of speech would be able to speak. - The art, based on what has been shown, literally imitates life.
There’s only one thing I can think to add to Lewis’s solid suggestion that the camera just wasn’t that big a revelation to wizard-kind, with the idea that they can immediately save someone’s image being likely and having, to a degree [as it’s only seen happening after they’ve died], been proven. That would be that the immediate convenience of the camera is why it’s used by their media, but when you think about it for a minute there doesn’t seem to be much use for cameras elsewhere. They use them, because several non-media photos appear throughout the series, but J. K. Rowling probably didn’t think it was worth her [or our] while to heavily involve anything as ordinary and benign as cameras.
Portraits, particularly the classically styled, life-like ones we see, are probably popular because of the manner of the enchantments involved in their creation. there isn’t modern art at Hogwarts because the people in the paintings are usually centuries old, hence the imagery and style of the artwork, and look like the real people did, hence the lack of cubism and whatnot.
There are few aspects of the Harry Potter universe which I haven’t given long, complex periods of thought…