1957-D LWC Mechanical Doubled Forehead, Nose And Chin!

As coop said on the 1957 coins, that machine must have been falling apart to produce so many mechanical errors. In different variations! My question is how did the die only produce doubling to Serra in parts of the coin and not the entire side of the coin where'd the doubling occurred? I'm imagining a die moving into position over the blank Planchet and it "Shifts" cresting the doubling! If that's the case how does it not double the entire side of the coin and only a small section? Is the die broken and just that piece shifts?