I stink at this. I can never tell from a picture if its raised or indented or just a stain or something in between. Only reason I ask is because I got a roll of new pennies once and nearly every penny in the roll had a die crack at that exact spot. If it is, that must be so incredibly common on that spot for some reason.
Not a die crack but it's a weak spot for sure. A lot of plating blisters occur there. Also plating blisters on the obverse giving it the effect you see.