This is a hard post to explain, but let me try. Most builders or people in general do not really care if the sheetrock’s distance to the window is exactly the same on both sides. But our builder does. He takes the extra effort to make sure that the window is exactly centered and straight on both sides.

It is hard to see them, but if you look to the left, you can see the shims in the wall to the left of the window.

Thanks Nathan!