This is a pictograph of a porter in which the head has been replaced by the noun consignment. He has a shoulder yoke. A pack is suspended on one side of the yoke, but on the other side a rope
hangs free. Hence, this is an ideograph for a partial load.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-328 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 83: Collections in India: Suomalainen Tiedeakatemia.