This is a pictograph of a measuring rod. There are four spaces which gives us four units of measurement. However, you should note that the marks between the spaces are diagonal rather than horizontal. This indicates that the measurement is estimated rather than precise. Therefore, the suggested translation for Mahadevan's sign number 2674 is 'roughly four units'.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-830 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 73: Collections in Pakistan: Suomalainen Tiedeakatemia.
Image Credit:
Indus Script Sign Number 2674: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.