Grease filled die, or slightly weakly struck. The area opposite Lincoln's bust sometimes doesn't strike up well. Certainly keep it if you like it, but there is no added value.
Sorry but no. As was said above, that area is generally weak due to the bust taking more metal to fill it's void. Even if a grease filled die it really wouldn't be worth more than face.
This happens quite a lot with modern Lincolns. After a bit of trial and error after switching from a solid .950 copper alloy to copper plated zinc, strike force on the dies was reduced considerably, resulting in frequent weak strikes. Yours is quite common.