sacrificial rice, rations, pay
糈 centers on rice used in a formal or sustaining context: rice offered in sacrifice, rice given as rations, or rice as a form of pay. The common thread is rice as a deliberate provision.
糈 combines 米 (rice) with 胥, which likely contributes the sound. The character is associated with rice used in offerings or provisions, but the detailed historical development of 胥 in this context is uncertain.
The left side is 米 (rice). The right side 胥 looks like a person receiving something. Picture rice being handed over as a sacred offering, a soldier's ration, or a worker's pay.
For ショ, imagine a show of gratitude where rice is offered: show -> ショ, and the rice is the sacrificial offering.