"A small decorative object." "Inexpensive, flashy, trivial ornament." "Knick-knack." "Curio." "Tangible small wonder."
I define trinkets by several qualifiers. Not all seven have to strictly apply, but the more boxes it ticks off the better.
A trinket is..
A whimsical object,
With unique physical characteristics,
Indicating no clear functionality,
Of a size that skews small,
With little or diminished monetary value,
But with a lot of sentimental/emotional worth,
And a narrative that's connected to it.
These qualities are what makes a trinket not just like any other object. These qualities make trinkets into tangible small wonders, into a character on their own, into their own subject.
And that whimsicality? The unique physical characteristics? The sentimental or emotional worth? And that narrative? We're going face the challenge of trying to translate all that into our visual work.
That's also part of what makes the visual development of a trinket different from the visual development from a prop. Both the interwoven character and narrative and starting from an existing physical object are what makes this so unique.