Exactly, the doodling is done by humans and the machine paints the HD images based on Renoir's original. I've edited the blog post to clarify.
What still isn't clear to me is how exactly that "workflow" demo (and consequently the "money-shot" final generated images) happened.
There is a progression of generated images with increasing quality. Who did which steps in those iterations?
Blog post uses ambiguous language: "N-th image tries / removes / fixes", etc.
It's not clear though if it was:
1) algorithm steps (keep computing more till generated image looks good), or
2) human being tweaking inputs to fixed algorithm (keep painting new input/output doodles till generated image looks good), or
3) human being tweaking algorithm itself (change code till generated image looks good).
The output gets better because through iteration the glitches are removed incrementally, and it converges on a final painting that looks good!