In Layer 3 with have 3 sections of light.
Infra-red Night vision
Artificial Light
Day Light
So this gives us a sense of the rebirth theme. Moving from darkness to light. The middle being artifical light - as if its a glimmer of hope. A room whose surrounding location is in darkness but via technology we able to light a small space.
I think this is a theme that Boyd has carried from the tigs something new music video. The about me section talks about its influence from the critical traditions from romantic theory called the mirror and the lamp. The glimmer of hope in a dancing candle flame amongst darkness.