unposed
Natural and not arranged or planned ahead of time.
Unposed describes a photograph or image where people aren't deliberately arranging themselves or putting on special expressions for the camera. In an unposed photo, someone might be laughing naturally at a joke, concentrating on building something, or just going about their normal activities without even noticing the photographer.
The opposite is a posed photo, where everyone lines up, smiles on command, and holds still while someone counts to three. Think of the difference between a stiff school portrait and a candid snapshot of friends playing basketball: the action shot feels more real and spontaneous because it's unposed.
Photographers who specialize in unposed pictures try to capture genuine moments rather than artificial ones. They might photograph a birthday party by staying in the corner with their camera, waiting for that instant when someone's face lights up with real surprise and joy. Wedding photographers often take both posed formal portraits and unposed shots of guests dancing or the flower girl making faces at the ring bearer.
The word can apply beyond photography too. An unposed question is one asked naturally in conversation, not rehearsed or planted. Someone's unposed manner means they act naturally and unselfconsciously, not putting on a show for others.