This is a pictograph of a house to which three tally sticks have been added. Hence, it is a house where a lot of counting takes place. This gives us a weights and measures yard.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-151 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 47: Collections in India: Suomalainen Tiedeakatemia.
Comments:
This is Mahadevan's sign number 271, which I have redrawn to better reflect the original.