On the Discover map, when you click the Show List button, a side bar appears that displays a list of all the properties that are visible with your current map view and selected filters. That means that every item in the list corresponds to a visible blue dot on the map.
Viewing this list of properties is not the same as tracking. If you want to track the properties in the list, click the Track All button in the top right corner of the map. Click here to learn how to track.
Note: If you can't see items in the list, then you may be zoomed out too far, or no visible properties meet your filter criteria.
Here's a video that describes how to view the list of visible properties: