rise, tower
聳 centers on something rising high and steeply, like a tower or a mountain peak soaring upward.
聳 combines 從 (follow, accompany) with 耳 (ear), but the historical reason for this combination is uncertain. It may have originally depicted something towering or rising, but the component relationship is not clearly established.
Imagine a giant ear 耳 rising from the ground, following 從 the shape of a towering cliff. The ear stands tall like a tower.
For ショウ, picture a show-stopping tower rising high above the city: show -> ショウ, and the tower soars upward.