After iExplorer is done transferring your music tracks in Media Library, it then will rebuild your iTunes playlists and restore anything else that is on your device but not in iTunes on your computer yet. The blue bar above it is another progress indicator though it can be a little inaccurate at times. As long as you don’t receive an error or a crash or a prolonged message in the lower left corner, then the program should still be working, and I would let iExplorer keep running. Or, you could press the Cancel button, and then restart the transfer anytime. iExplorer can detect what tracks are already in iTunes, so it will just pick up where it left off and only transfer tracks that are on your device but not in iTunes yet.