If we are to be consistent about our conclusions, then it should be diagnosed as
Die Deterioration Doubling. The reverse is definitely
DDD, we have seen that on quite a number of nickels.
Cujohn, several folks here have asserted that
DDD can also move towards the center on certain coins. I would find that plausible on the nickel reverse, for example, because the Monticello device is a huge cavity on the die. I would actually like to know that for certain, since it seems to come up fairly often on current coins, and on nickels in particular.