Yes, I understand that you drew this and your w.i.p. I've already seen the w.i.p and I know you did some slight changes from the original image But what I'm trying to say is that you could give credit that you used the reference.
But of course overall, as usual your art is amazing and you're well-talented. I did realise some of your art is based off visual, like your Rozen Maiden traditional drawing. I know you're not claiming that you didn't copy from visual but you're also not giving credit. You don't have to give credit as long as you're not claiming which you're not...but it's be respectful if you did.