Apparently this is the only post in Danbooru where Aya is presented as an harpy.
Actually, showing her as anything between purely human (plus wings) and purely crow is sort of unusual. I can think of only two other pictures of her on here that show her in between, one where she has bird feet to hold onto a telephone wire (though otherwise human) and one where is is in full karasu/werecrow form(though with such a short beak she looks more like a black feathered songbird than a crow.)