I'll admit that I tend to be a bit of a visual perfectionist at times. I've been known to straighten random pictures in people's homes. I've also been scolded from the wife for doing it in public places, usually restaurants. I really hate it when they are screwed to the wall and can't be leveled... Lol. That being said, I also wouldn't have noticed it had you not said anything. It may not be centered, but it looks perfect visually, and that's what matters.