I think this is a brilliant idea! I've been noticing an increasing number of public domain images on Pixabay recently, with some Pixabay members taking credit (maybe unintentionally) for other people's work.
When I first started using Pixabay, about five years ago, I uploaded about 10 photos, but I was surprised that only one of them was accepted! I think it was a basket of fruit or something. I've never received any payment for it, but it has received a few votes of thanks. I have sometimes "bought the artists a cup of coffee" but at the back of my mind I wondered how much went to the artist and how much to Pixabay.
I wonder if a platform could be built where you could upload images and pay a very small amount of SBD to download them, say $0.05 (which could later be an SMT), with 10% going to the developers and maintainers of the platform. That way, downloading four or five images wouldn't eat too much into the overall profit of a post. And creative types might be able to earn a bit of SBD from designing shareable memes.