Comment 2 for bug 258091

I understand that it should show a warning, but again, you don't need *ubuntu-artwork*. You need ubuntu-gdm-themes for the recommends.
Having ubuntu-artwork pulls in all of this stuff:

The following NEW packages will be installed:
  gtk2-engines-murrine human-icon-theme human-theme ubuntu-artwork ubuntu-gdm-themes ubuntu-wallpapers
0 upgraded, 6 newly installed, 0 to remove and 10 not upgraded.
Need to get 7573kB of archives.
After this operation, 11.6MB of additional disk space will be used.
Do you want to continue [Y/n]?

11 megs is very valuable space for LiveCDs.