Seems that my portable scanner handles black & white lineart better than colour images. You know it’s bad when you can take photos off a smartphone and the colours don’t look as broken up. It may be time to set up the printer/scanner I bought but haven’t had time to unbox yet.
I should also note that the image of the girl in the blue dress is actually a re-draw of an older (at least 2014?) image. These are the two side by side. The older one is on the left.