"Information about the map and the panoramas"

You can click in an empty area of this map to search for the nearest spherical panorama in a certain radius of 150meters. If after the click, a panorama is found then it will appear in the window on the left plus a respective Pin icon and a Google Street view icon will appear in the central map too

You can drag the Google Street View icon to a new position or click in a new area to search another panorama.

Finally by pressing the recenter icon you can recenter the main map to the selected Google street panorama.