The map of where your visitors came from
Under the chart is a map and a list of the cities your visitors were in. It is worked out from their connection, so it is roughly right rather than exact, and somebody on a phone or a VPN can land in the wrong place entirely. Read it as a shape rather than a record. It is most useful for one question: are the people looking at your site in the market you are trying to work in. If they are not, that is a sign about where you are being seen, not about your site.