Funnily enough quite a lot of artists use early digital cameras, where the quality is described as 'grainy'
Its of just bad enough quality (and hasn't been altered by algorithms) that you can get a 'sense' of the scene without too much detail, being over/under-exposed, etc.
I think this is a perfect post to bring up the theory of Vermeer's work presented in this film, "Tim's Vermeer." The focus of the movie, Tim Jenison of NewTek, hypothesized the use of a mirror to allow an almost paint-by-numbers recreation of the sitting subject.
Its of just bad enough quality (and hasn't been altered by algorithms) that you can get a 'sense' of the scene without too much detail, being over/under-exposed, etc.
Edit: also see the use of a 'black mirror' https://londonfineartstudios.com/the-mirror-the-black-mirror...