options for running "switchdesk"?

[Robert P. J. Day]

  for the first time in a while, i wanted to test switching
from GNOME to KDE as part of a demo, so i selected:

Preferences
  More Preferences
    Desktop Switching Tool

then selected "KDE", and also selected "Change only applies to 
current display" (wincing only slightly at the ugly syntax of that
last choice).

assuming that that last choice meant that it would affect only this
current session, what does it mean to immediately be prompted that
my desktop configuration requires X to be restarted for the changes
to take effect?

is this a temporary, one-time-only change or not?  sure is confusing.

rday