Moonshell and ImageViewer are two totally different things. They do not interact or share files.
If you're trying to open the Image Viewer .nds file and it says "not supported adapter" you might be using the unpatched version of Image Viewer. Make sure you are using the Image Viewer .nds file that has already been patched for the R4. If you don't know how to patch it, you can get the pre-patched version from www.r4ds.net. Once you have the patched .nds version, just run it from the games menu, and it will pick up the ipk file and show you the thumbnails.