That's what Incused lettering looks like when it has ejection/mechanical doubling, imo. If it were a Doubled Die, with that amount of 'spread', you'd see other design elements doubled like that. I'm fairly certain, even without a closer photo, that there are no Raised design elements that are doubled, or if they are, they look like mechanical doubling. Do you see any other design portions doubled?
I think the idea is that if it is a true doubled die, many elements should show the doubling. Check out the infamous 1955 DD Lincoln.
This may help explain incuse machine doubling. There is also an image of an Olympia National Park quarter with fairly extreme incuse machine doubling. http://www.error-ref.com/incused-machine-doubling/