I want to say feathered, but that's been taken for another technique (fenicio). I haven't seen this given a name anywhere. In fact, I don't think I've even seen the precise effect before. It looks like smears of colour with bubbles round the edges. How would you describe it as it's not totally clear in the pictures? It's relatively modern Nason piece, isn't it?
We could have a competition to provide a name. Would that help end your misery?
Nice bird, btw, whatever we call the technique.
David