EVE displays items on the screen in the order of the display list. Therefore, items further down in the display list will be layered on top of items further up. A shape or image displayed towards the end of the list can therefore be overlaid on top of the earlier screen contents. This is useful for adding a menu or message box over the top of the user interface. You can use the Alpha setting (COLOR_A) to give the message box partial transparency too for an improved visual effect.