WHAT EVEN ARE ANDROIDS ACTUALLY
For personal ref but also general ref; some of this is headcanon/extrapolation. WIP as I try to get together extra canon materials that might have more info.
NOTE: The primary in-universe driving purpose in all design elements of YoRHa androids was creating something as close to the human image as possible; this would reinforce the emphasis of their role as specialty weapons created directly by humanity, to fight for humanity. As a result, features of their appearance and function that would generally be superfluous or impractical for military robots become justified by the fact that "it makes them mimic humans better". Is this a good justification? Well, that depends on who you ask ¯\_(ツ)_/¯
( (mystery ghost music) )
NOTE: The primary in-universe driving purpose in all design elements of YoRHa androids was creating something as close to the human image as possible; this would reinforce the emphasis of their role as specialty weapons created directly by humanity, to fight for humanity. As a result, features of their appearance and function that would generally be superfluous or impractical for military robots become justified by the fact that "it makes them mimic humans better". Is this a good justification? Well, that depends on who you ask ¯\_(ツ)_/¯
( (mystery ghost music) )