By using layer blending this sample "highlights" a neighborhood on the map. The neighborhood is given a "halo" and the area surrounding it is blurred using multiple layers in the webmap.
Either use the search or click on the map to highlight a neighborhood. There's a restriction on panning and zooming once a neighborhood is highlighted, so it will always remain in view.
Use the screenshot functionality to make a screenshot of the current map and download it as an image to your harddrive.
Thanks to Ruben Bruining for the inspriation.