Looking at it I see two things that make it "advanced". One of the narrowness of some of the pieces, but even more difficult is the closeness of the appliqued pieces to each other - a lot of them are right next to each other.
I would say try to make a few pieces of your own. Try the fans with the long narrow curves placed at a point at the center and fanned out at the top. Also try a few pieces where you place two pieces butted up to each other (unless the technique is to applique one on top of the other?).
So try making your own. Just use a few pieces scrap and cut them as close to some of the shapes and place them similarly to the shapes.
One other thing if you decide to go for it. I see that a lot of the pieces, especially the fans, look like hand dyes with graduated hue. Not sure if that will be important to you or not to achieve the same affect.