"Princess, we have a visitor. We picked up something outside the base's zone 12 moving east."
"It's metal."
Have a kick-ass heavy metal riff play here, perhaps some old school Metallica. You could also have the riff replace the "scanner of the system... scanner of the sys" sound the probe droid makes.
If you wanted to get really fancy, you could try to construct a mini metal song, sampling "it's metal" and other pieces of dialog from the scene/movie.