File Sharing on an Unusual Network Setup

I've searched the forums and cannot find anything that addresses this specific setup. My primary computer (which has all my music, movies and other media on it) is an Intel iMac running leopard, connected to my wireless router via ethernet. In my living room I have a PPC Mac Mini running leopard, connected to the router via wifi, which has no problems whatsoever detecting and connected to all the media folders I have shared across the network from my iMac. Both of these macs running leopard are fully up to date.

The problem is I have a B&W PowerMac G3 in my living room running Panther which is connected to my network via internet sharing through the Mac Mini. Being as the PowerMac is connected through the Mini it can see the shared folders on the Mini, but it does not see any of the shared folders across the network on the iMac. Is it not possible to see shares across the network when running through an internet share, or am I doing something wrong?