No, you can ignore that part. The image isn’t showing how to accurately draw a head onto a surface, it’s showing how this given head drawing would look in different projections.
Projections from what? You don’t need a projection for a drawing, it’s already a 2d image.
Edit: I realize that you can use it to compare the different projections to each other, but it doesn’t show which one is more accurate overall. In this image it looks like they used the globular projection as the "default’ with the most realistic drawing, and created the others based on that, but they could have picked any one of them to be the default.
No, you can ignore that part. The image isn’t showing how to accurately draw a head onto a surface, it’s showing how this given head drawing would look in different projections.
Projections from what? You don’t need a projection for a drawing, it’s already a 2d image.
Edit: I realize that you can use it to compare the different projections to each other, but it doesn’t show which one is more accurate overall. In this image it looks like they used the globular projection as the "default’ with the most realistic drawing, and created the others based on that, but they could have picked any one of them to be the default.
Yes, again, that’s the point.
It assumes the sphere projection is correct, and shows how each of the 2D projections isn’t correct. This isn’t hard.