It's actually not the buttons, it's the pressing. The cloth is rather loosely woven and the pattern lines are somewhat liquid. Notice how they really don't look straight anywhere. If you fold back the placket on the left side, you can see that where it joins the body of the shirt, the pattern is matched perfectly. But in pressing, they got misaligned. This is far less common with a more tightly woven cotton.
I'm not talking horizontally. Vertically the sequence of patterns is not matching.