1962 D Washington Quarter RPM/Machine Doubling?

How can we tell? Note the overall shape of the mintmark. It is normal in size. But the area you are looking at is affecting the normal size. On a RPM there will be spread between the punches of the mintmark process. If normal there will be no spread, but then there is spread, it is called a RPM. But You are in for a treat. We are going to examine the V.V sites RPMs, to see what was going on that year, and why Machine Doubling is not part of a RPM. Ready?

Now you see why these are RPM, with MD on some of them and the MD has nothing to do with the RPM. We I spot this, I knew It was going to be a point that all would like to have explained.

CoopHome : Does a Machine Doubling count as a RPM? (An explanation of the 1962-D RPMS)

I would have to say no. It just looks like Machine Doubling. If the bottom serif has a split there, it would be a minor RPM. But it is not one of the listed dies. Note the affected area is on the mintmark itself. Not an added mintmark, like a RPM would be.
Note on this RPM you can see two distinct punches of the mintmark punch, with a spread between the punchings:



That is the difference between a RPM and a machine doubled example. Just the normal mintmark was affected on the OP's coin with Machine Doubling.