OK, I figured out what's happening here. Here are the steps I took
First I just started with a new image -- set @ 420 X 300 pixels, advanced options 'Transparency'
Next in the ToolBox dialog, I chose (or clicked on):
Gradient Tool
Then I chose the Gradient 'Metallic Something'.
Look @ the Gradient Options and make sure your 'first' selection is 'Mode:' Normal
Then, use the gradient tool in the image (move gradient from top to bottom) I use CTRL then left mouse button to drag a straight line.
Once you've done that, go back to the ToolBox dialog, and change the Gradient 'Mode:' to Difference.
Go back to the image and 'click' in the image as many times as you want (I did about 10).
NOW, you can go to the 'Filters' menu item in the Image dialog, and select
Filters->Distorts-Emboss
My settings are:
Azimuth 58.24
Elevation: 41.03
Depth: 11
It looks more like foil that way...
Here, you can play with the settings and change it a bit (in the Emboss dialog)
Hope that helps!
-Don