Usually lacing is when the pattern color edges the feather, with the base color on the inside, unbroken. This guy has the base color rimming the feather, and the 'pattern' color is on the inside, completely unbroken. Technically, it's 'penciling' but there is no penciling on the inside, just solid pattern color. That's the really unusual bit.
I didn't even notice it until you mentioned it. I very much appreciate your knowledge and your willingness to share it!!
(not only in this instance... I've seen many informative posts from you!)