Nope, as geometry was not my favourite subject, and writing in a different language does not help.
Alright, I'll try again. Here is another analogy.
- Find a tall oak tree that is standing alone in a large level meadow.
- Make a temporary mark on the tree's trunk about 6 feet above eye level. Perhaps you might tie a yellow ribbon around a branch near the trunk.
- Stand on the ground about two feet from the trunk.
- Measure the angle above eye level to the mark.
- Stand on the ground about two-hundred feet from the trunk.
- Measure the angle above eye level to the mark.
- Note that the angles differ.
Your head--Satellite--ISS camera
Mark on trunk--North Pole--horizon
The angle varies in all of the three cases. Yes, it will vary less in the last case, as the ISS does a good, but not perfect, job of keeping the same side pointed down to Earth.
I hope that helps.