Created attachment 110190 [details] screenshot open system settings use a file from your hard disk to set a new user avatar in user-manager or a new sddm background in login screen (sddm). right click system settings entry in your plasma panel. The file selected from your hard disk is listed as recent file.
I think that's just kactivitiesstats support in the file dialog.
A file used to install a gtk theme locally via "Gnome/gtk application style" kcm is also listed in the list of recent files.
I mean, technically, these are in fact recently-used files. :)