From Connolly and Dodge, The Ancient City

These women may be the ergastinai or weavers of the life-size peplos or perhaps just attendants.  Note that one woman who has turned to looks at the woman behind her is carrying an incense-burner.  Frankincense was burned in these containers to enhance the experience of the sacrifice with a sweet-smelling odor. Others are carrying jugs (perhaps wine for libations) and bowls (probably for pouring libations).