The display-line-numbers-mode introduced in recent Emacs versions is
very nice and works very well generally.  However, org is not aware of
it and this causes a minor problem with the display of the header line
in column view mode.

The line numbers are displayed between the fringe and the actual
contents of the lines and so the text starts some distance from the
window border.  The header has no line numbers so starts immediately
after the fringe.  See attached image.