Butterflies

Butterflies are a symbol of the revolutionary spirit and passion for resistance felt by both Christine and Joan. Christine has a tattoo of butterfly wings on her back, and she describes Joan going into battle accompanied by butterflies. She also notes that the CIEL scientists attempted unsuccessfully to create synthetic butterflies. The fact that they were unsuccessful is meant to contrast CIEL with the leaders of the resistance.

The Panopticon

A Panopticon is a type of prison designed in a circle with a guard tower in the center. The guard can rotate his/her position around the tower to view the inmates, who cannot see the inside of tower to know if they are being monitored or not. The Panopticon is a symbol of CIEL's oppression and perversion of technology, as the guards are all robots, and the inmates are also under video surveillance.

Joan's Song