ceremonial jeweled implement
璋 centers on a ceremonial jade object, specifically a jeweled implement used in formal rites. The meaning is narrow and tied to ritual regalia.
璋 combines 王 (jade) with 章, which likely contributes the sound and may relate to a decorative pattern or emblem. The character denotes a specific jade ceremonial object.
The left side 王 (jade) tells you it is a jeweled object, and the right side 章 suggests a patterned emblem. Picture a carved jade scepter used in ceremonies.
For ショウ, imagine a ceremonial show where a jeweled scepter is displayed: show -> ショウ, and the jade implement takes center stage.