The Moon's rotational speed

[Mirage]

these pictures of the Moon are not identical to each other. Each picture shows the area where you have squared in different areas, and more or less craters have appeared. As for the last image, the area was a completed build of Griever. When the game starts, the image of Griever on the Moon starts to build itself.

The Moon next to Ultimecia's Castle is very big. This proves that the Ultimecia Castle doesn't take place on ground (Earth's)... But the Moon from the 'ending' part looks also big. Perhaps, the Balamb Garden has gained a new ability of flying in air space?

Two of Skyblade's pics are incomplete, but even if they weren't and you were correct, there isn't any less-than-debatable evidence that the Moon is rotating (anymore than an hour, anyway) faster than our moon. There is also no indisputable evidence that I can see that Griever only forms near the end. The two pics before Griever "is visible" are too distant and fuzzy to tell conclusively that the image of Griever isn't already there. Unless you can provide evidence (much like an interview with Final Fantasy VIII team member), I'm disinclined to believe this image is only visible near the end of the game.

BTW, that's an interesting concept to believe that they've developed the technology to allow the entire Garden to travel skyward enough that the moon would look bigger. That's a Garden ability that previously only the Guardian Force Eden had.

Yes, it does look different. For example, if the Moon from one of the pictures has more or less craters than another, then it's different (not the same).

The appearance of craters (more or less) is not evidence of change/difference in the moon's rotational speed.

The apparent size change of the moon could just be because it had a more elliptical orbit than our own moon.

-edit-
Actually, I thought of another thing that could make the moon look larger, like in that last screenshot with the garden. It's possible that it's because of the way the scene was shot. If the garden was far away from the camera, it'd look smaller, while the moon would be the same size. Then, if you used an "unusual" zooming technique, the moon would appear much larger than it actually was. I'm not sure exactly what it's called (focal length, maybe? idk), but I've seen it in other photos or videos.