Sorting directories to be first is very easy with the MATE desktop environment. Install the dconf-editor if you do not already have it. Then navigate to /org/gtk/gtk4/settings/file-chooser/ this contains the setting we need to change.
![The dconf-editor open on the Linux MATE desktop.](https://www.securitronlinux.com/wp-content/uploads/2023/02/dconf-file-chooser.webp)
The sort-directories-first option needs to be changed, this will enable this very useful option. But I still can not get icons in the file picker on the MATE desktop. This is very annoying.