screen
扆 centers on a screen, specifically a standing partition used to divide space or provide privacy.
扆 combines 户 (door) with 衣 (clothing), likely representing a screen or partition made of fabric or used near a doorway. The exact historical development is uncertain, but the component combination suggests a screen associated with a door or clothing-like hanging.
Imagine a door (户) with a piece of clothing (衣) hung over it as a makeshift screen to block the view.
For イ, picture an easel (イーゼル) with a screen draped over it: easel -> イ, and the screen hides what's behind.