The idea in one line. Provenance is the passport of a signal: source, date, place. An observation without a passport cannot cross the border between opinion and evidence.
Why it matters. Any image can be beautiful; only a documented image can be weighed. When you know WHERE a look appeared (runway, street, resale platform, feed), WHEN it appeared (date, not "recently"), and WHO carried it there, you can judge how strong the signal is and whether it is growing. Without provenance, two students arguing about a trend are just comparing tastes.
The three fields, always. Source: who published or wore it — with a link or a precise name. Date: when it appeared in the world, not when you found it (a 2022 photo discovered today is a 2022 signal). Place and context: city, event, platform — a look on a Copenhagen street and the same look on a Milan runway are two different signals.
Example. "Burgundy is back" — no passport, no value. "Burgundy total looks: Bottega Veneta FW26 show (Milan, February), then three street-style appearances at Copenhagen Fashion Week (August), resale searches for burgundy bags up on Vestiaire since September" — three passports, one verifiable claim.
Common mistake. Citing the aggregator instead of the origin. Pinterest is where you FOUND the image; the show, the shop, the street where it was TAKEN is the source. Always dig one level down.
Check yourself. Open your current moodboard and pick any three elements. Can you name source, date and place for each within a minute? Whatever fails the test is decoration, not evidence — keep it if you like it, but never build a claim on it.