The depiction shows two of the four Caryatids. The woman on the right has her hands tied behind her back, while the one on the left is covering her eyes with her hands. They perform the work of columns: their necks and shoulders support Ionic capitals, on which the architrave rests. The word Caryatid comes from the name for the inhabitants of Caryae, who took the side of the Persians against the Greeks. After the Greeks defeated the Persians, they slew the men of Caryae and turned the women into slaves and beasts of burden.
Additional information:
The woman with her hands tied is a symbol of punishment, while the weeping woman stands for repentance: a crime led to punishment and repentance.