From the booklet:

This garment is 3” narrower at waist than at bust.

Sleeveless top with armbands, lapels, waist-shaping details, and button front. Both yarns are worked together throughout.

Materials:
5(5, 6, 6) Berroco Jenny, #1225 Lagoon, 135 yd. ea.
7(7, 7, 8) Berroco Linor, #3720 Pistachio, 100 yd.ea.
3 buttons, 3/4”