The Image list let you see and alter which pictures are currently selected on the chart.
This is the last downloaded DSS image, or images from your Archives.

You can select which images to display by a selection in the first column. This selection is valid only as long the chart position and FOV is not changed. Click OK after you make your selection.

You can also view the FITS header for the selected file or open the Archives setup.

If you are connected to a SAMP hub you can send the selected image to another SAMP application.