I'm happy tulle skirts are poplar right now. Sewing all that tulle can be daunting and I give tips about dealing with so much tulle in that blog. BUT, I'm sorry to hear many people are confused by the inner yoke I created.
First I want to explain why this seemingly unnecessary piece is there. It's purpose is to keep the bulk out of the waist seam. If all the layers of tulle were wedged into that waist seam, it would be very bulky and the elastic would have trouble snapping back to it's correct size. The whole waist would sag.
And, as always, I'm happy to do my best to answer questions.