1994 D Lippy Washington

When you look at the affected areas, note that they are flat, not contouring like hub doubling would create. Machine Doubling affects the outside edges of devices. The movement of the machine causes the damage on coins devices. Flattening the devices. When you look at various devices, the same thing happens creating false doubling on ears, facial areas on the bust. Always looking the same. Flat, shelflike, changing the devices, removing the contours on devices/designs. A doubled die has the doubling on the die, not created by the machine. Usually in a single direction across the whole coin, sometimes in several directions or affecting limited areas. MD has no rules and can vary from strike to strike. But tends to affect outside edges of devices.

How does MD happen just at the lips and not along the entire left side of the profile?

I agree, Machine Doubling.

Here is a 60x magnification of both lips, and two 120x magnifications of the lower and then the upper lip. The extra area isn't flat, but raised.