Added the cover art too and that shows up too.
If you also want the cover in the FLAC files created on the' External Encoder' tab, you need to add
%hascover%--picture="%coverfile%"%hascover%
to the 'Additional command-line options' on that tab.
-T "artist=%artist%" -T "title=%title%" -T "album=%albumtitle%" -T "date=%year%" -T "tracknumber=%tracknr%" -T "genre=%genre%" %hascover%--picture="%coverfile%"%hascover% -5 %source%
If you also want the 'album artist' tag added when you fill the 'CD Performer' field
-T "artist=%artist%" -T "title=%title%" -T "album=%albumtitle%" -T "date=%year%" -T "tracknumber=%tracknr%" -T "genre=%genre%" -T "albumartist=%albuminterpret%" %hascover%--picture="%coverfile%"%hascover% -5 %source%
If you rather have the 'album artist' tag added always by the 'CD Artist' field
-T "artist=%artist%" -T "title=%title%" -T "album=%albumtitle%" -T "date=%year%" -T "tracknumber=%tracknr%" -T "genre=%genre%" -T "albumartist=%albumartist%" %hascover%--picture="%coverfile%"%hascover% -5 %source%