This is a pictograph of a length of rope with a loop at the end. Hence, it is an ideograph for the verb to hang.
Illustrative Text Reference:
Harappa: Seal impression: H-1721 A: Asko Parpola, B. M. Pande, and Petteri Koskikallio, 2010: Corpus of Indus Seals and Inscriptions: Volume 3,1: Page 241: New material, untraced objects, and
collections outside India and Pakistan: Suomalainen Tiedeakatemia.
In inscription H-1721 A, this symbol is around three quarters of the full character height, and is placed at the top of the character area.