Personality trinkets
The small quirks that add up to make someone their unique self. Could be a recurring inside joke, the way they loop their Ys at the end of words, the fact that they love almonds and love chocolate but hate when they're mixed together, their love of anything velvet and forest green; any of the multitude of small things that might remind you of them.
A: "What are all those things on that new album cover?"
B: "Oh those are some of the artist's personality trinkets"
B: "Oh those are some of the artist's personality trinkets"