Watches In Local Variables View
The Blue Jewel icon allows you to merge the Watches and Variables windows together in one. When you do this, the Watches Window is removed from the tabs in the Output Window to avoid redundancy. This feature is often useful when you want to see both together, but probably not the best to leave enabled for performance. This is because the watch has to read the data for all variables and not just the local ones. Select the icon again and the watches will return to their own tab.
Application
In addition to local variables, access to Global Variables and PIC® Special Function Registers (SFRs) is commonly needed during a debug session. The Variables Window has the capability of displaying watches ( i.e. Global Variables and SFRs) in addition to local variables. Accessing watches in the Variables Window is accomplished using the two lower control icons. The center icon controls whether or not to show watches in the Variables Window. When watches are enabled, the lowest control icon becomes active and you can click on it to enter a new watch into the Variables Window.The image below shows a screen shot of an SFR being displayed in the Variables Window
Local variables will be displayed next to a green rhombus . while watches will be displayed using a diamond icon .