The flatness can be the result of a weak strike, but the darker areas, the areas that have lost frost, is where you have rub.
Back of cap
Top of cap
Above ear
On cheek
On neck
On nose
Front hair
Eagles chest
Eagles legs
Wreath
All these points exhibit frost breaks, indicative of light wear. I'm betting this coin never circulated, but spent time in an environment where it was allowed to slide around a little, hence the term slider.