In this Indus sign, the important man is combined with two glyphs that each mark the beginning of an area. The first glyph marks the beginning of the important man's area, and the second glyph marks the beginning of the neighbouring area. Hence, this is an ideograph for the important man's domain or realm.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-184 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 52: Collections in India: 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 2634: 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: BabelStone Blog: https://www.babelstone.co.uk/Blog/2007/07/old-hanzi.html: Accessed: 5 November 2017.