Package Info
You can display detailed information for the selected package (in the update list or the package list) using the Actions menu or the Cmd-I keyboard shortcut. 
A short description from the TeX Catalogue is displayed, and documentation obtained from Texdoc is shown as clickable links and as thumbnail icons.
The bottom area show all files associated with the selected package which are currently available in your system.
You can enlarge the icons to readable size with a slider that appears if you hover near the top of the thumbnail display.
Use the spacebar or Cmd-Y to show a Quick Look-style preview panel for the selected documentation file.