From this tab you can browse from a list of 6 (November 2011 release) reference dataset experiments. Each reference dataset outlines the stain, the target of the stain as well as the staining pattern.
Selecting the experiment ID will launch a contact sheet viewer. Clicking on individual images in the contact sheet viewer will launch a Single Image Viewer (SIV). From the SIV you can adjust the brightness and contrast of each individual channel by adjusting the slider bars.