The obverse die looks like it is a lot older in use than the reverse die. So it may be
Die Deterioration. If it were a doubled die, I doubt it would be strong enough to list. But I'm thinking it is die wear or die abrasion to remove clashes. Quarters go through a lot of vending machines and slot machines. So it could just be circulation damage. The obverse looks pretty weak also. I would think it is a spendable coin.