The Temporaries Pane shows a list of temporaries in scope at the current execution position in the selected stack frame.
The list also includes the receiver of the message, 'self' and may also include additional unnamed stack variables identified as _stackN (where N is the distance from the top of the stack). Typically, when about to return from a method, _stack0 will show the value to be returned.
Adjacent to the names of the temporary variables in the Temporaries Pane are the temporary values. These are displayed as the #printString of the object held by the variable. A workspace is also provided in the Inspector Pane for you to assign new values to the temporary variable slots.
A full Inspector can be opened on the selected temporary using Workspace/Inspect it.