Renders sell the event. Twins run it. The difference is whether the visual is connected to the objects, rules and live state underneath.
A render is a picture produced once, at a moment, from a scene that is discarded afterwards. A twin is a persistent model of the venue in which every visible element maps to an object with attributes, constraints and history.
That distinction becomes concrete during changes. Move a stage two metres in a render and you have a new picture. Move it in a twin and sightlines, camera positions, egress paths, rigging load points and the truck manifest all update, because each of those consumes the same stage object.
Twins also carry time. The same hall exists in a build state, a live state and a breakdown state on the same day, and a portfolio view can show all three simultaneously across halls. Cinematic presentation is then a rendering mode of the operational model, not a parallel asset someone has to keep in sync.
Practical test: ask whether the visual can answer an operational question. If it cannot tell you whether the room still passes egress after the change, it is a render.