In Playlist Sharing, you don't get some of the information for a song, like the disc number, or the artwork. The playlist sharing window doesn't have disc number as an option for the information you can see in View Options. If you click Get Info you can see it. Weird. But worse is that if you stream the file, you don't get the artwork. It's right there embedded in the file, before the actual music; you'd think iTunes would/could pull it out.