In order for you to be able to see at a glance what myCloud Desktop is doing at any given moment, various symbols are shown on the myCloud icon.
myCloud Desktop is currently synchronising files between your computer and myCloud.ch.
myCloud Desktop has a notification for you (e.g. an update). You can find more information about notifications here.
An error has occurred. myCloud Desktop is not running as it should be.
All of your myCloud files are synchronised.