The taskbar on Windows 7 and later can show a progress indicator. If Picard is busy with long running operations, e.g. web requests for a large collection or saving a lot of files, it would be useful to make use of this to indicate progress.

Qt5 allows accessing this with https://doc.qt.io/qt-5/qwintaskbarbutton.html

See also https://community.metabrainz.org/t/wishlist-progress-shown-in-windows-taskbar/447056