Zoom in and select a polygon in the left side map pane to view image in right side pane.
The image that you download (link in polygon popup) is a GeoTiff and will load as an orthorectified product in a GIS. Some users with a GDAL based viewer (QGIS) may need the associated .vrt (Virtual Raster) file. It can be downloaded from the same location by changing the .tif to .vrt. Both the tif and vrt file are included in the bulk download tar file.