A guided walk through the nested rings for Barcelona. Neighbourhood. City. Region. Stop. Then look up at the limits above.
The narrated version of the aggregation atlas: the nested rings — a neighbourhood inside the city inside the region — read step by step, for anyone meeting the Index without slides. Each step shows what the people at that level log in a typical month, how often it lands, and the sentence that hands off to the next ring. A status pill on each step marks its data as partial (some real Barcelona feeds) or mock (sample values).Step 3 is the governance ceiling: the adding ends there. Below that line, steps 4 and 5 shift into the limits register: italic, lower density, read as observation, not adding up.
The walk takes a minute and a half. It is the version a mayor, a lab lead, or an outside reviewer can be talked through without slides.It is also the test of whether stopping at the region holds up: by the time the ceiling appears, the reader should already know why the next two levels are watched, not added up. If they do not, the page has failed.
↪ Return to the aggregation atlas · drill into the embedding prefix relationship · or examine the per-pillar transition rules.