In Mahadevan's sign number 8039, the orientation of the adjective stop-start is changed. The different orientation indicates that the stopping and starting is taking place on one spot. Hence, this composite symbol is an ideograph for the verb to jostle.
Illustrative Text Reference:
Kalibangan: Seal: K-43 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 306: Collections in India: Suomalainen Tiedeakatemia.
Image Credit:
Indus Script Sign Number 8039: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.