I think we are splitting hairs. I don't think the mint intended to do anything. I think a die starting wearing and needed some additional polishing...so they polished it rather than replace. As a result, the coins from that die reflect that change. Is that an error...is that a variety? I don't know what to really call it. Maybe one day it will be a VAM.
I would honestly disagree with this. Coins are not made to look perfect...they are made to be easily produced for circulation. This is why we have lower relief coins today and why dies are used until they are worn out. These coins are meant for use and need to be produced in large numbers. When dies start to show signs of wear...they are polished or otherwise refurbished to get as much life out of them as possible. I think what we have here is a coin that was produced from an older die that had been refurbished a bit.
I would like to, but the computer i am using will not load my pictures right now. I looked at some of the old ones I have and They did not have the same appearance as the newer date ones before 2008. I have some that have the heavy details between the legs. Others that I have, have heavy details of the tail feathers, which you could call like the Mercury dime rev as full split lines. They are very detailed and not washed out or polished out as you above have said to the other area.