You right-click on the other's nickname in your queue (down, up, or waiting). Then a new search window opens, and maybe it displays the other users file list.
However, most users have disabled the option in their preferences (either for everybody, or just for not-friends). Thus, in most cases you get no file list at all.
If you disabled the option yourself, you can sometimes see the msg in your log: "Client xyz asked to see your filelist -> rejected" or something like that.
Regards.