It doesn't look like a legitimate rpm. I'm thinking some type of small lamination or platting issue. I couldn't get any closer with these pictures. These modern looking mint marks are not very impressive! Any guesses?
Split plating - very common around the D mint mark as the plating pulls away from it. http://coinauctionshelp.com/copperplatingissues.html#.Vw78HsvSaI4
We've seen so many of those "RPMs," we ought to coin a name for them. I got one. Let's call them, "eBay RPMs." You got a nice "eBay RPM," there. Good find!