Here are some pictures to give you a feel for what it looks like. I completed the pattern as spelled out and you will see there is a huge difference in the sides.
Picture 1: The entire Brim
Picture 2& 3: Building Edge - Back and forth with turning
Picture 4&5: the Decrease Edge - binding off each row
As you can see, on the decrease side of the brim, it's very choppy and stair steppish, whereas the building side where you knit, and turn to build the curve is very smooth.
I'm not exactly sure how to sew this together where it doesn't look like utter crap since it will be at the very edge of the brim.