Originally Posted by VectorZ
Hard to tell what I'm looking at. Can you take a few other pictures?
His photo shows an extreme closeup of the rotor/wheel interface with the rotor on the left and the wheel on the right. I suspect, as another poster noted, that these are drainage features for water that can get in under the center cap.
He just needs to take the wheel off and look at the underside. It should be pretty obvious if it is normal or not.