This component graph shouldn't be confused for a dependency graph; it is rather an inverse of that. It shows, for each of the 2200 kanji, which kanji reference it in their KanjiVG descriptors. The first kanji per line is a dependency of all the kanji that follow it on that line.
The list of 1670 kanji is the subset of the total list of 2200 Remembering the Kanji, Volume 1 (6th edition) kanji that are not referenced in the KanjiVG descriptors for those 2200 kanji.