Sorry about the late commentary. It was only just now that I realized I forgot to write it up.
So, I've decided to deviate from the original CBCL and mention Dr. Light's past and reason for studying robotics. He built Rock and Roll, in my version, to fill a void in his life where Richard and Rachel had been. If you look closely at the silhouettes, Richard and Rachel look almost exactly like two of Dr. Light's robots. If you can't figure out who, I don't blame you since one of them has yet to appear in this comic.