The directional figure eight should be tied in one way or the other depending on which way the loop will be loaded.
The directional figure eight (a.k.a. inline figure-eight loop) is a loopknot. It is a knot that can be made on the bight. The loop must only be loaded in the correct direction or the knot may fail. It is useful on a hauling line to create loops that can be used as handholds. It also provides a place to attach a Z-Drag to the line when prusiks are unavailable.