PieFed is a link sharing platform so every post has a 'url' field. By embedding the post url into the RSS feed entry, we get images in our feed if the posts have images. The example I gave in the earlier toot uses images but it could be anything, including video or audio.
Podcasts are just RSS feeds with audio files. This means #PieFed is also a federated #PodCast platform - every community is also a podcast, if the things you post in the community are just links to mp3 files.