The Indus Dictionary Project
This symbol is comprised of three elements: the noun weight; the verb to indicate; and, a point of light. It is the verb to weigh in the adjectival form weighing.
Harappa: Seal: H-473 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 281: Collections in Pakistan: Suomalainen Tiedeakatemia.
There is only one extant example of this Indus sign.
To Weigh: Lynn Fawcett, 2017.