I can't get it done within Mp3Tag right now. For example, I see the correct picture in Windows with the album 21 by Adele. THE REASON: BECAUSE I also have a jpg file in that folder with the name of the album, so 21.jpg. I see that image in Windows, but I see a different image in my Android device. That is another picture INSIDE the FLAC file and it has to be removed. I am very curious to see an answer which can help me, I am busy now for a long time.