This is a pictograph of a storage jar with a pointed base. The little roof shape represents a lid.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-810 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 70: Collections in Pakistan: Suomalainen Tiedeakatemia.
Comments:
There is only one extant example of this Indus sign.
A similar jar, but without a lid, is currently (December 2017) on display in the Hotung Gallery at the British Museum¹.
Image Credit:
Indus Script Sign Number 2364: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.
Note:
1. https://www.harappa.com/blog/british-museums-new-ancient-indus-exhibit: Accessed: 19 December 2017.