This is a pictograph of a wall. Therefore, it is the noun wall.
Illustrative Text Reference:
Harappa: Pottery Graffiti: H-2549 A: Asko Parpola, B. M. Pande, and Petteri Koskikallio, 2010: Corpus of Indus Seals and Inscriptions: Volume 3,1: Page 351: New material, untraced objects, and
collections outside India and Pakistan: Suomalainen Tiedeakatemia.
The alignment of the bricks in the pictograph indicates that we are looking at the wall from above.
Inscription H-2549 A refers to the perimeter wall at the point where the pottery was found.