This is a pictograph of a flag with five streamers attached to it.
Illustrative Text Reference:
Harappa: Seal: H-66 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 184: Collections in India: Suomalainen Tiedeakatemia.
Comments:
This is Mahadevan's sign number 170 which I have redrawn to better reflect the original.
There is only one extant example of this Indus sign.
Image Credit:
Flag with Streamers: Lynn Fawcett, 2020.