what it means here is that the items that follow pertain to / contrast with the item on the line above--the particular qualities of a 'listener'. sort of an outline, or a list.

i do not know what they mean when some others use them, but when i use an indent, i use it as a visual clue: hey reader--look this stuff is about the thing it hangs off of.

actually, it is up on another site without the indents, because i misformatted it, and decided to leave it. i think it is subtly different. i also think that the way it appears above is more appropriate to my meaning, oh mysterious one.