Drop Dialogs are dialog windows with 2 states: maximized, or "normal" size, and reduced. The maximized state gives access to less commonly used controls. The size state is changed by clicking the [Show >>] and [<< Hide] buttons on the right side of the dialog.
The Palette Properties dialog is an example of a Drop Dialog
Click [Show >>] to switch to the maximized state like this:
Click [<< Hide] to switch to the reduced state like this: