Some observers on Pixiv seem to think this image is not very erotic despite being a full nude; perhaps this is related to the closeness in feel to a piece of classical art? Or perhaps it is simply the slovenliness she exudes?
Certainly, I feel no compunction in reproducing such an image on the front…
He actually has two versions of this Horo, though the revisions are too subtle for me to discern (the old version is on his Pixiv profile). The image was created with Sai and Photoshop CS3, despite its rather analogue looks.
Some more of his ravishing works:
He lists his occupation as “humble graphicker”, implying a CG artist or similar (he is tagged Type-Moon on Pixiv), and says he sometimes likes to create these illustrations. Alas, he is not very prolific.