From Simple Modern Sewing:
The wide, scooped, rounded neckline of this design makes it easy to put on and take off -- just slip it right over your head. Wear the sleeveless style as a camisole or wear a sweater underneath. The cut is loose enough for a comfortable fit even when layering. The body pattern is the same for each of the three variations, but the different sleeve treatments give each its own style. Be sure you have the butterfly-sleeve blouse in your wardrobe!