In its essence the use of the term is to convey to the reader that the particular author means ,,, well, whatever the reader infers. It's a fuzzy, descriptive term which authors use without giving any idea to the reader what it is they are trying to convey. Too many writers cannot convey clarity of thought. They are usually writing so as to be read, not understood. It's just something a reader must contend with when reading untrained writers who do not know how to "write" an easily understood picture.
Again this is simply my opinion. Many writers have clarity of thought but, no idea how to convey same when putting thoughts into words.
Back in the day when letters were how we conversed over distances, trained writers wrote a letter, set it aside, reread it the next morning, revised/edited the missive until their thoughts were easily discerned. Most of us, using the immediacy of the net, no longer do that. The result is flame wars, misunderstanding, lack of clarity, hurt feelings and so forth. It's simply a part of the times we live in.