#Phosh's file selector (pfs) picked up existing 馃憤-nails of files since some time but didn't create missing ones. @arunmanij fixed that by creating a thumbnailing service. The file chooser calls into this service to request the creation of the missing thumbnails.
Having things in an extra service allows us to experiment with different implementations (it currently uses GnomeDesktopThumbnail under the hood) and also to sandbox things further if desired. Since pfs is used by our portal implementation all apps using it (including #flatpak s) will leverage that automatically.