These are various collections from the net. If you try to use one format where another is required (say, a gif for an icon) , fvwmconf will first look for a duplicate, then call netpbm if that fails. I notice things move a bit faster when browsing if you have all the duplicates already.
To use these with fvwmconf, just upack them in your home directory. They will go into directories in ~/.fvwmconf/images . Of course, you don't need any of these-- the image selector can browse image collections that you already have.
Here is a file of sample configurations that include just enough images for the configurations. Unpack these in your ~/.fvwmconf directory