I just purchased a download and this time decided on the format .wav rather than FLAC. Of course with .wav the metadata is not embedded as it is with FLAC and ID3. The download included a separate file of a .jpeg of the album art. However ( as I anticipated) Mosaic seems not to associate the FLAC files and the .jpeg even though they are in a shared folder. So there is no display of the artwork at either album or track level.
Thanks a million, The download vendor had the .jpg file named as per the album name. Changing it to “cover” ( in the same folder) successfully associated it with the music data in Mosaic.
Interesting that “cover.jpg” works - the standard is “folder.jpg”. At least, that’s what the various meta-data taggers like Yate and dbPoweramp put in the folders when you ask them to.