You can add an image to illustrate media that does not have a preview!
You can add an image to illustrate media that does not have a preview! To display a representative thumbnail of your audio media, zip files or other formats that do not have automatically generated thumbnails, you can apply an image or a pdf to the file. Go to the media details, click on the pencil in the top right hand menu.
Select the 'Replace cover' option and drag the image or pdf of your choice. The media now offers the image in the mosaic and the detail. Please note! The 'Replace Cover' feature only becomes available once the different media formats have been generated.