I ssh to a remote host (without X forwarding).
In the shell created by sshd on the remote host, why can't I start a GUI program on the default
$ eog Unable to init server: Could not connect: Connection refused (eog:31542): Gtk-WARNING **: 23:11:16.793: cannot open display: $ echo "$DISPLAY" $
while specifying explicitly
$DISPLAY=:0 creates a window on the remote host?
$ DISPLAY=:0 eog (eog:31546): dbind-WARNING **: 23:11:42.415: Error retrieving accessibility bus address: org.freedesktop.DBus.Error.ServiceUnknown: The name org.a11y.Bus was not provided by any .service files
:0 the default value of