First layer: Literally yes, there's fog everywhere. It gets around.

Second layer: Interesting contrast of something clean and natural meeting something industrial and dirty. Voices, who is speaking, where from, and with what perspective? Themes of liminality / phase-change / obscured visibility / motion. Those tiers of shipping mean that some other stuff besides fog gets around.

Third layer: Generalizing a bit, if natural things enter into a blackened, dirty hub of artificial industrial and commercial activity, they can become unclean.

Questions: Is man not also natural thing? Foreshadowing: What happens to the heart and soul of a man in an overcrowded, dirty, artificial setting? Can what was once clean and then dirty be made clean again? What does all the motion actually move towards? Where will the shipping go, and will the fog see the meadow again, and will man be able find his heart?

This seems like something way beyond reading comprehension though. Personally, and this is not a knock on you, but I don't find any of that imagined perception to be interesting/valuable. All this sentence is saying to me is that the author is trying to portray a dark, grim, barely visible image of the city.

Comprehension is a spectrum that starts somewhere superficial and merely "adequate" but also stretches into deeper literacy/fluency. On one end of the spectrum it is about reading between the lines, but that doesn't mean it's purely subjective nonsense. As for whether it's interesting or valuable, if you want to stay on the surface that's fine, but it's a narrow point of view to imagine that's all that is there.

Not sure if you've got an engineering/math brain with no taste for art, but I'll put it like this in case it helps. Who cares about the infinitude of primes, I mean it's just numbers and what could be interesting or valuable in that? If you're thinking squishy crap like literature and critical theory sort of sucks because you're craving something more hard and objective, maybe try to come at it from the point of view of semiotics[0], which is an adjacent topic, but also closely related to stuff like linguistics, formal semantics, cognitive science. Frege worked on this kind of stuff when he wasn't busy being a giant in mathematical logic [0] https://en.wikipedia.org/wiki/Semiotics

You're dug in, but none of this is what the linked paper is about (perversely).

It's about students who are literally unable to parse sentence structure and grasp what's being described in a scene—ones who think that Michaelmas Term is the name of a character and that the image of a hypothetical Megolasaurus walking up the street is an actual dinosaur in the scene.

Try reading the paper linked here to see what the discussion is about, rather than (as the authors of the paper criticize) just guessing at what they should have meant.

In general, I think that's a perfectly valid view for you to take. It's not the only one, but it's a valid one.

In specific, this study was a test of reading comprehension, for English majors at a university level. They should be expected to do better with a complicated sentence then "it's really foggy, I guess". Just as I expect someone in film school to be able to give a more detailed review of a movie than "It was pretty good, you should go see it", even though that may be a perfectly acceptable review if a friend gives that to me.

I don't know why you're yes-anding the premise. For this sentence the authors of the study would have been rather more interested whether the subjects would look up the term "aits".

Aside from that, there's actually isn't a lot more to it, which makes it an unfortunate sentence to focus on, because it results in a caricature of the study. "There's just fog everywhere" and "the author is trying to portray a dark, grim, barely visible image of the city" are just barely short of the desired results. It just happens that this mostly straightforward (not complicated) sentence lies between/among many other far less straightforward ones. The problem is glossing where it is inappropriate to do so—and being overly comfortable doing so—which the authors of the study criticize as "oversimplification":

> 96 percent of the problematic readers used oversimplified phrases at least once to summarize a sentence in the test passage while 61 percent used this method for five or more sentences. Often, subjects used this tactic as a shortcut when they became overwhelmed by a sentence with multiple clauses. One subject disclosed that oversimplifying was her normal tactic[…] Those subjects, however, who relied on oversimplification became more and more lost as they continued to read

Without reading the paper… There seems to be fog everywhere - but it’s the beautiful and natural fog of London intermingling with the stinking haze of pollution. The use of “great” is interesting because it seems like the city was about to be presented as “bad.” But there’s more to it.

I think in that sentence the fog isn't really that important, it's just an excuse to tell you about the surroundings.

The speaker is probably standing near city limits. There is some sort of dock or shipyard down the river, there is some green nature stuff up the river. The river might come up later as a reference for other locations.