This is useful for #musicians in the #musodon who want to publish their songs on Mastodon: if you add a cover image to the MP3 file before attaching it to the post it will look much nicer!
Huh, turns out in newer versions of Mastodon (I'm using v3.5.3) you can choose the cover image after you attach the MP3 to a post! And you can also add a text description. #til