The edge of the die near the rim of the die has been tapered from die polishing. This leaves a raised ring on the outside of the die/internal edge of the rim. The gutter on the outside of the die creates the rim:
Note lower right image. So inside that edge that forms the rim, is where the die was reduced. (a reduction on the die, will leave a raised edge on the coins struck with that die) The the crisp line has been altered in that affected area.
When the die was hubbed, the die needs to be set for the correct size. So note the die on the right that has not been tapered. On the right you can see the die set to required specs. You can barely see the area that forms the rim. This is also added to the die after the tapering. It is necessary of the the rim creation.