Comment 1 for bug 774751

Actually, the same mounted volume appears in Nautilus in three distinct ways.
Say an USB key, named "PWI-ANY-8G":

- on the desktop, is seens as
  uri=x-nautilus-desktop:///PWI-ANY-8G.volume
  mimetype=application/x-nautilus-link

- in computer view, is seen as
  uri=computer:///SMI%20USB%20DISK.drive
  mimetype=application/octet-stream

- when mounted in /media, is seen as
  uri=file:///media/PWI-ANY-8G
  mimetype=inode/directory.

Nautilus-Actions doesn't alter in any way the uri and mimetype passed by Nautilus.
It is up to you to write a profile for each these three modes.

Regards
Pierre (Nautilus-Actions maintainer)

Ps; and you'd rather open such a bug in upstream
https://bugzilla.gnome.org/enter_bug.cgi?product=nautilus-actions