If you can mount the NAS with NFS, then that's a possibility for accessing the NAS, and one advantage to this is that it acts transparently like any other part of the file system, so any tools that work with the file system (like the Images application) should be able to work fine.

I've had a few complications with mounting over NFS, though - firstly, you need root access to try anything at all, and loss of the wireless connection tends to uglify things (I've had trouble unmounting when the connection is not there, for example). Also, I've had issues playing large MP3 files (>200 kbps) over NFS, e.g. occasional audible clicks in playback.

I'd love to try and get automount working so that I don't have to remount every time I want to access an NFS directory, but I haven't even experimented with it; I don't even know if the necessary tools are available.