look at Fig. 3.
Are you looking at a solid or hollow sphere that I have photographed?
Is it again the case that at first you see this earth as a solid (convex) sphere?
A satellite takes photographs
in the same way inside the hollow sphere called earth. In this photo, subsequently,
the earth does appear as a solid sphere.
Please consider, that the earth in the photo on the left, actually shows a hollow hemisphere of the inside world (earth) model shown in Fig. 2.