It's clearly a dick shape
>>723650985
Okay, so I've got some experience here. I've played a fuckton of games and most modern games use skydomes rather than skyboxes.
Going by the lack of distortion in the middle though, usually introduced by equirectangular projection, I'm going to have to say Earth uses a skybox.
Cube, final answer.
Clearly you have never traveled.
>>723650985
Earth is a nigger