ornamental hairpin
簪 centers on a decorative hairpin used as an ornament, often made of bamboo or metal, worn to secure and adorn hairstyles.
簪 combines 竹 (bamboo) with 朁, which likely contributes the sound. The character originally referred to a bamboo hairpin, reflecting the material and function.
The top 竹 (bamboo) suggests the material, and the bottom 朁 looks like a pin piercing through something. Imagine a bamboo hairpin sliding into a hairstyle to hold it in place.
For シン, picture a shiny ornamental hairpin: the word 'shiny' starts with シン, and the hairpin gleams as it secures the hair.