From the website:
an additional diagram in PDF format showing the construction of Row 17 which forms the sleeve openings:
Row 17 Diagram PDF

From the magazine: Doris Chan combines the best of both worlds in this wonderfule piece: the drape and style of a shawl, the ease and comfort of a sweater. Crocheted in rows from the top down, with easy V-stitch increases, the garment will make you think you are crocheting “just” a shawl until you fold down the wings and join them to form armholes. The sleeves are then worked in the round from armhole openings to cuffs. There’s no finishing, so once you’re done, you’re ready to show off your newest creation.