German SS officers wearing their hats to the side?

I'm hoping a third reich expert can help me on this, but I was looking through some old portraits of SS officers and I noticed a lot of them wear their hats tipped to the side, or slightly askew, but rarely straight, like a military hat should properly be worn. I even saw a photo of General Rommel doing this. What does it mean when they do that? Is that their way of saying "I break the rules sometimes, that makes me a bad***."?