In this Indus sign, Ishtar is combined with two glyphs that each mark the beginning of an area. The first glyph marks the beginning of Ishtar's area, and the second glyph marks the beginning of the neighbouring area. Hence, this is an ideograph for Ishtar's domain or realm.
Illustrative Text Reference:
Mohenjo-daro: Impression stamped near the rim of a pottery goblet: M-1372 A: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 180: Collections in Pakistan: Suomalainen Tiedeakatemia.
Comment:
This usage of the beginning area glyph can be likened to that discussed in an article by Andrew West on the difficulties of incorporating old hànzì characters into Unicode. Andrew gives an example of an Oracle bone inscription in which the names of three royal ancestors are written using a mirrored C shape for the character bāo¹. Bāo is combined with the second character of each rulers posthumous name, so that Bāo Yǐ, Bāo Bǐng and Bāo Dīng might be read as: the reign of Yǐ, the reign of Bǐng, the reign of Dīng.
Image Credit:
Indus Script Sign Number 1011: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.
Note:
1. Old Hanzi: Discussion: Andrew West, 2007: http://www.babelstone.co.uk/Blog/2007/07/old-hanzi.html: Accessed: 5 November 2017.