Why Does the Moon Appear Upside-Down in the Southern Hemisphere?

Globe defenders often claim that since the Moon appears right-side up when viewed from the Northern Hemisphere and upside-down when viewed from the Southern Hemisphere that this is proof positive of a spherical Earth. They believe that observers standing in the Southern Hemisphere of their spinning ball are literally upside-down relative to observers in the North, and that this is the only possible reason the Moon could appear inverted when viewed from opposite hemispheres. Anyone can easily debunk this flimsy claim for themselves however by simply taping a picture of the Moon to their ceiling and viewing it from opposite sides of the room. The Moon will appear right-side up when viewed from one end of the room and upside-down when viewed from the other. There is no need for the entire room to be spherical, nor for observers to be standing physically upside-down relative to one another to explain this simple phenomenon.

On the Flat Earth model, the Moon as well as the Sun, are always located somewhere between the Tropics spending the majority of their time on or near the equator. So just like the picture taped in the middle of the room, people viewing from the North will see the Moon appearing right-side up while people viewing from the South will see it appearing upside-down. This phenomenon is therefore easily explainable regardless of whether the observers are assumed to be standing upside-down on a ridiculous spinning ball or right-side up on a logical level plane. Deeper investigation into the matter, however, reveals details that definitively determine which one it is.