the robot alchemic drive wiki says that nanao loves bread and water soup which is a pretty insane way to misread that scene but also so wikia wiki

"but he does nothing to advance the plot" have you considered: he's just a silly lil guy

the wire mother knows the cloth mother will never give her the relationship she actually wants but is too attached to the warmth she gives her, and the cloth mother jars with the wire mother's demeanor and the heaviness of her ideals but finds her too useful to abandon

said this as a joke but now my brain is beginning to fire about the concept of a woman who is gentle and comforting but ultimately emotionally unfulfilling and a woman who is sharp and unemotional but works hard for those she loves having the messiest relationship