iTunes 11 has multiple cloud icons that symbolize a wide variety of information.
Four new cloud icons are displayed prominently throughout the latest version of iTunes.
The dotted cloud is displayed when iTunes is actively processing and syncing the file with the cloud.
The exclamation point cloud shows when a file could not be placed into the cloud for any reason.
The double clouds icon is displayed when the the cloud has identified a duplicated file. You can click the icon to remove the duplicate.
The down arrow cloud is displayed when a file is available in the cloud but it is not currently on your device. These are the files in the cloud that can be hidden if you desire. These files can be downloaded to your local machine by clicking this icon.
