The Roman goddess of fruit is usually shown with fuller flesh. Perhaps this depiction of Pomona means to suggest moderation, in diet and in the gentle way she waters a vine. Too much water, or wind, or any of the elements isn't good for growing things.
Pomona
Depicted on the seal of the former Erasmus Hall Academy
Outside the Erasmus Hall campus, Bedford Ave. at Erasmus St., Flatbush, Brooklyn