A friend sent me this photo, asking if it is some type of error. He says it just "looks" different. I have little knowledge in errors. Any help is appreciated. Thanks in advance.
I'm see evidence of a worn die strike. You can see striations and pitting on the field. Not really a mint error. Just a die deterioration issue. The reverse looks ok because they probably replaced the obverse die and continued using the reverse die at the same time.
I agree with Ed. Dies are expected to deteriorate so details/devices/appearances will change. Cracks and die chips are arguably the same but deviate from the specifications in a more abrupt/significant way. These are borderline errors and sometimes labeled as a variety...but I still think it's die deterioration. But that's just me...