pearl pendants on coronet
璪 centers on ornamental pearl strings used as ceremonial headwear, specifically pendants attached to a coronet.
璪 combines 王 (jade/jewel) with 喿, which likely contributes the sound. The character refers to jade or pearl ornaments, specifically pendants on a ceremonial crown.
The left side 王 (jade/jewel) suggests precious stones, and the right side 喿 looks like a cluster of hanging beads. Picture a king's crown adorned with dangling pearl pendants.
For ソウ, imagine a soul (ソウ) of a pearl shining on the coronet: soul -> ソウ, and the pearl pendant glows with inner light.