>>1896534OR here. I appreciate you filling it so quickly! I do like it, for the most part. Like the other Anon said, the addition of her third eye would be nice, just to make it more recognizable as Koishi, but that's not really a big deal.
Overall, it looks really good. I especially like how you drew her pubic hair. That's exactly what I was looking for. The only minor nitpicks I have, aside from the absence of her third eye, are the lack of visible feet (which is understandable with the position you went with), and something about her expression doesn't quite look right to me. It's really cute, but rather than sheepish, to me it looks more...inviting, I guess? Given she's able to make herself difficult for other people to notice, the unspoken dialogue I had in mind with the picture was along the lines of "O-Oh, um...y-you can see me..." Sort of that mousy, deer-in-headlights expression where the sheepish smile is all she can think to do.
Like I said, though, what you've done here is still great. I would very much appreciate something closer to what I described in here, but if you'd rather not, I can't exactly hold it against you. Thank you, once again, because this is great.