What is double-image cartography on a Globe?

A double-image globe is always also an illuminated globe, as a different map image is displayed in the unlit state than in the lit state.
In the unlit state, you see the physical map image of the earth with forests, deserts, mountains, but also underwater trenches, such as the trench off Japan.
In the illuminated state, you can see the so-called political map image, which shows the national borders of the countries.