I assume on simpler sequences, it is one main image with just a few "moving parts"....
So, for example....in this scene, you have the main non-moving Milia image, while the shoulders drop down and the "blank" area next to her torso is the "animated" arm she is using to plug-in her Q-Rau controls.....sadly those individual douga sheets were not in the set I bought...just the shoulder dougas....
Sadly, this is a disappearing artform...certainly it has disappeared from Macross completely since Macross 7 I believe....it's all done via computers now