This image is unavailable on Donmai. Go to Danbooru or disable safe mode to view (learn more).
Artist's commentary
Hang in There, Kogasa-san 2205
They really did tell me this, so I was shocked. :-) I figure they could differentiate by the strength of the light or the way it scatters or similar, though. I was put out by having the explanation cut short on me, but hey, what are you going to do?
Tomorrow, things become more incomprehensible! :-)