I believe that when both a lossy (JPEG) and a lossless (PNG) version of the same image is available, the lossless one should be the parent. This is not explicitly stated in howto:post_relationships, but it makes sense and is in line with the "Most Original", "Highest Resolution" and "Cleanest" rules.
The new version uploaded by Shebadotfr is a PNG. The JPEG artifacting in this version is weak, practically invisible on my monitor, but I have used GIMP ("Sharpen" at sharpness >90) to confirm that it's there. I have also confirmed that the PNG version isn't a lossy-lossless conversion.
