The visualization tracks consignment movements by filtering query sets for departures from and arrivals at base locations, distinguishing deliveries, collections, and items in transit. It shows the flow of goods between origins and destinations, with transit defined as the union of completed deliveries and collections. The code relies on Django’s queryset API with `Q` objects for location-based filtering, using `exclude` to isolate timed events, and combines results via set union. No specific charting library appears; the rendering approach is not visible in this snippet, focusing instead on data preparation.