jade tablet
珽 refers to a jade tablet, a specific ceremonial object. The meaning is narrow and concrete, centered on this single artifact.
珽 combines 王 (jade) with 廷, which likely contributes the sound. The character was created to name a specific type of jade tablet used in ceremonies.
The left side 王 (jade) tells you the material, and the right side 廷 suggests a formal court setting. Picture a jade tablet held upright in a royal court ceremony.
For テイ, imagine a jade tablet placed on a tea tray: tea -> テイ, and the tablet rests there like a ceremonial object.