I created a quick app that allows you to display album art in a dashboard for music played on a Sonos from Spotify. It won't work for everyone's use cases, for example it only wors for Spotify music but it meets my needs.
You can find it here - GitHub - craigde/hubitat-SonosAlbumArt: This is an application that allows you to select a sonos device and then creates a tile for use in dashboards with the album art for the playing track for use with HUBITAT.
It has a dependency on the File Device Manager written by thebearmay so install that first from HPM.
If there is interest, I can add it to HPM.