"What do you need boy robes for?" inquires Madam Malkins.
"I'm sometimes a boy," the girl explains.
"What?"
"Look—"
"… I'm sort of confused here. They're made, and it's using magic, and I'm pretty sure they just have them act like the person, they're not copying the person or– storing them in a picture, or anything?"
"Okay but that doesn't mean they're not a person, even if they're not the same person."
"I don't think magic usually makes people, though. I'm not saying it's totally impossible – but I'm pretty sure if they were people, it'd be the sort of thing people know? They're not exactly badly treated, they're usually considered antiques and stuff, but I'd expect to know."
"Okay, but you still haven't told me how they're not people, since they talk and stuff."
"Sort of… how if you were writing something down on paper, I could write back like I was someone, but that someone isn't actually a person? It's just someone I'm pretending to be? It's that but magic and automatic, I think."
"Right but you were a person, even if you were pretending to be someone else, and you'd be doing something only people can do, which is talk, so there's someone doing a thing there."
"… The person who produced the magic for the portrait, is what I was thinking…" Blink. "This is not actually, you know, what it is – I haven't asked, it hasn't made me ask this, I just treat them, uh, as I would treat a magical portrait? Try to be polite, they vary in personality, I'm related to a couple of them?"
"Um – no, I – maybe? My great-uncle has a portrait here but he's not usually actually – in the frame…"
"I'll see if he's there and if he's not mum can probably floo-call my aunt – he might be with them?"
"Yes that works. Can't you, like, knock on their portrait or something?"
"… Not that I know of, at least? Some portraits might have that enchanted in, that might be a thing people can do?"
His mum, however, is perfectly happy to go have a chat with her sister to ask if he's up for visiting, and apparently he is!
"I mean, do you have a personality, and memories, and desires, and preferences? Do you learn things, get bored, feel happy and sad and all that?"