On page 29 it looks like the picture for "None" represents a structure that is just covered with soil/fill/dirt on top of it. We had a similar scenario in the picture below. Only earthen material is used to keep the below culverts in place. So this would be "None" not "Other"?
I would call this 'None' - it isn't structured enough , to me, to be considered a headwall, and appears to be more like normal road fill.
Tom