That appears to be split plate (no added value) doubling on the mintmark. It is because of the poor production of plating a solid zinc core with a micro thin copper coating. Since late 1982 there are many, many anomalies on cents because of this
Plate doubling on Zincoln's is common, which is why I don't even bother looking. Read this for more information: http://www.lincolncentforum.com/plating-split-doubling-split-line-doubling/
Okay, I read it and I kind of understands, but how do I tell the difference between this and doubled dies, they look so alike. Just post them to coin talk and let the experts weigh in. When I saw the penny, I researched it, it looks like the doubled die. What tells you/me that it's this phenomenon? How do I know when/if I've found a true doubled die? I understand why you don't look, it's easily mistaken, yes? I finally recognize machine doubling, now this...
This chart might help you some! Notice how the Hub Doubling appears to be about the same height? Also notice the notch and extra thickness! On the machine doubling imagine in your mind a worn die striking the planchet and slipping some as it strikes. That causes the flattened (some call it shelf like) appearance! Hope this helps! Probably better ways to explain it so anyone who can help please do so!!!