How to intrepret selectedData property of choropleth_mapbox

When I look at the selected data output on a choropleth_mapbox chart, the data seems to contain information on ‘points’ and ‘mapbox’ coordinates. What do these represent? They don’t seem to bear any 1:1 relationship with the number of polygons I select.

I would like to get a data structure that tells me which polygons on the map have been selected. Is there any way to do this?