That looks like a spherical earth to me. I agree.
Next, I believe the OP was also questioning how it relates to the earth, and how that model works. In previous threads we did talk about that. A spherical geographical system using flat maps beneath, as iampc referenced on page one. Workings of this spherical model is a deeper question, and would take much more research for team ball to demonstrate their claim. You know our arguments, already, as you have been involved in multiple discussions on this matter.
If, you have forgotten the discussions, or, if that link isn't working for you, I am more than happy to paste all content here for you or any curious person.