Picard sorts the tags (like “Title”, “Artist”, “Album”, “Track Number”, “Length” and “Date”) in the metadata pane (#6) alphabetically:
You can adjust your “favorite” tags in Options → Options → User Interface → Top Tags
By default, the 6 Tags mentioned above are always shown first.
But there is one more option:
“Show changes first”
This setting appears if you right click on one of the tags in the metadata pane (#6):
I hope that I can remember this post after my next fresh installation of Picard