The glittery paint adds interest to the art piece- though it makes it harder to scan. Think of Kaiteki Art for example- she uses a TON of glittery and shimmery paint and it in no way detracts from her work. I think it might be a more western perspective to see it as lessening the seriousness of an art piece?
I don’t know if it’s western only or not - I know that my teachers in the US definitely wouldn’t approve! But I asked one teacher here if I could use it and he was like, yeah sure. I agree about scanning! I only use it when like I am experimenting / the painting is “just for me” and not something I’m trying to monetize. I’ll check out that artist!