My 1909-S, VDB cent has a rim almost just like that. I always chalked it up to some weird rim strike during it's lifetime. But that was just so I could compartmentalize it. I think it is some odd delamination or planchet error of some kind.
My reasoning may be flawed, but the way that it stands away from the rim leads me to think this was post mint. If it was in the collar this would have been shaved away. The little point in the center looks like a grab point to hold it in place while some carving was done which pushed the soft copper outwards. The why and at this certain place will be a mystery forever as it does not match a possible jewelry scenario. Not sure if I said that correctly but I think you might understand what I'm thinking.