The text in Note 1 may contain no links to any other notes, i.e. no outward/front links.
However, Note 1 may have Note 2 linking to it, i.e. Note 1 may have a backlink from Note 2.
The Graph View shows the links between notes as lines. It does not show whether the line represents a front link or a backlink.
It would useful if the lines could be arrows instead, thus showing the exact link relationship between notes. And if Note 1 has a front link to Note 2, and Note 2 has a front link to Note 1, then the Graph View should show that as a double headed arrow.