I can't find any references on this coin so I am assuming it is damaged or possibly a die chip where the mint mark would be.
I am not sure either, It could be a grease filled die or it could be plated or lacquered. Maybe some of the error experts will know!
Is it just a 1927 P? If so and the extra thing there is raised, it's a die chip. This is when a piece of the die literally chips off and the metal there is not compressed so it remains higher than the fields. If the extra thing is part of a mint-mark, then the die probably had some piece of metal or something like that there which blocked the die from compressing the coin metal in that area.
If it's for sale and it's under $20, I would recommend buying it. The condition is already MS62+, but I would need to see the luster to determine a grade. It has very good details though.
No offense but I wouldn't pay more than a few dollars for that coin. Unless it is truly high grade. But it doesn't appear that way to me from the photo. The die chip is not a valuable error, and I don't like the grainy, porous looking surface on both sides.
