Aoi has four fingers. The parent post has the fixed version.

Edit: This image reached 1000 bookmarked on pixiv, so it belongs in the Pixiv 1000 pool. The artist didn't actually update the image on pixiv, rather, the fixed version was posted in an external link in the image description. Therefore I've decided to place this original image that contains the error in the pool instead of the fixed image, but if anyone feels that the revised image should be in the pool instead, feel free to change it.