Huh, that's confusing: it looks like a clean vector image, yet manages to have both aliasing AND anti-aliasing artifacts, and additionally 16-bit banding on the gradient part.

Also, the child post is tagged with idolmaster, is that actually correct?

It's a crossover/parody of Haruka from Idolmaster Xenoglossia (same hair ribbons and pose), and this pic is from his DVD release which has high-res versions of most (all?) of the pics from the site.