It's a cross between a shawl and a jacket! Choose 6 colors of fingering weight yarn (I used Roamer, but Gutsy Fingering works for non-wool)and blend them from front edge to back then back out to the other front. The sleeves are worked in "afterthought" method using the remaining amounts of yarn.
There is one size to this garment. As the designer and a woman who has been a size 2 and a size 20, I can appreciate your skepticism. However, you can see from the photos that it indeed does look nice on the tall, slim model at the Stitches West fashion show as well as on a curvy woman. The reasons for this are that the only "fitted" place on the garment is the space between the sleeves, aka the shoulder width. Regardless of our weight, height or bone structure, most females have a shoulder width that doesn't vary much, plus knitting is forgiving.
So knit it with confidence and take your time. It's a WHOLE lot of stockinette! Take it on trips and to knitting groups where you don't have to concentrate.