This problem appears to be fixed after updating to the latest Gnome packages in Ubuntu 21.10. I think this bug report can be closed.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1945742 Title: [upstream] Attach dialog default layout leaves very little room for file list because of the image preview To manage notifications about this bug go to: https://bugs.launchpad.net/thunderbird/+bug/1945742/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs