Alternately, it could just use the same lower right-corner popup as when it finds a new ISBN, as that's less intrusive.
EDIT: Specifically, this is the problem I have: while it's working fine here, once in a while other dialogs get stuck behind an inactive 'scan failed.' Thankfully all the times it's happened to me there was enough of the title bar peeking out so I could click on it to switch.