The main panel of this wrap is knit flat in a long strip, then stitches are picked up along one long edge and a scalloped border is worked. The border draws in the edge somewhat and the final, un-gathered shape is approximately trapezoidal.

From the designer:

My inspiration for the Sasanqua Wrap (named for a variety of flowering camellia) was a dainty wrap made to slip around your shoulders when wearing a tank top or strappy summer dress.