Note you are looking at the outside edges. Look for the spread on the centers of the devices. MD- is very common 1968-1972 cents. Even doubled dies will show
Machine Doubling on a doubled die. Only a doubled die, can strike a doubled die coin.
Machine Doubling is caused by the machine and can happen on normal and doubled dies:

Note the centers of the date devices. How they are wider in the centers. Now note the yellow arrows? Those are the areas that are affected by
Machine Doubling. Note the affected areas are flattened. Not showing spread, like the hub doubled areas. Look at the centers of the devices, not on the outer/inner areas of the devices.