Only a part of the Plot Page need be displayed on the graphic device (if any). This part is called the Viewing Window, (not to be confused with the Box). This window can be modified at any time using the command ZOOM. When you define a new plot page, the window is automatically reset to the full plot page. Changing device does not modify the Viewing Window.
This window has no effect at all on the metacode file produced by command HARDCOPY, which always contain the full plot page.