Comments on the content are always appropriate, as is a "Get a room, people!" razz when conversations get too insular (if you want to be less funny, you might suggest the Fanpop chat feature instead).
As to your first question: many users of video sharing sites (such as YouTube) like to use the site to share copyrighted music with their friends, and so they make "videos" that just have the album cover or some static text as a visual while the music plays. Others, who are slightly more advanced, make slideshows of static images for the same reason. Generally this is because either there is no music video, or there is a music video but the copyright owner insists that the video sharing site remove the music video every time it's posted. There may be other instances of still pictures with music, but I have yet to see any on Fanpop. Basically they're amateur copyright violations.
As to your first question: many users of video sharing sites (such as YouTube) like to use the site to share copyrighted music with their friends, and so they make "videos" that just have the album cover or some static text as a visual while the music plays. Others, who are slightly more advanced, make slideshows of static images for the same reason. Generally this is because either there is no music video, or there is a music video but the copyright owner insists that the video sharing site remove the music video every time it's posted. There may be other instances of still pictures with music, but I have yet to see any on Fanpop. Basically they're amateur copyright violations.
