These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Unbelievably inhuman creatures with plenty of tentacles arriving from outer space, beings so immeasurably alien we don't stand a chance in fighting them, and implications of our own inevitable doom in a universe that at best seems completely indifferent to what happens to us, not to mention a certain degree of insanity that comes from realizing our insignificance. Sound familiar? Well, good ol' HP Lovecraft would have been a child when this book was published, predating just about everything he wrote.
The name of the military leader that battles the Martians at Weybridge and Shepperton? Brigadier-General Marvin.
The book's references to the use of poison gas by the Martians were scary enough in 1898, but after World War I...
A similar thing happens in the Orson Welles version. Their take on the Thunderchild scene involved a bomber performing a Heroic Sacrifice by crashing into a Tripod. A tactic the Allied servicemen in the Pacific would become all too familiar with a few years down the line...
The artillery man in particular is a disturbingly prophetic figure. Even though he does not have the will to follow suit with these plans, the ideas that came up with do sound a lot like the things that thirty years latter by a group of people in Germany with good dress sense and a tenancy to march without bending their knees led by a certain rejected art student.
At the year 1898, the thoughts of a war so brutal that entire cities could be destroyed to the ground en masse were considered as paranoid nonsenses and wild fantasies, especially if they were about this kind of war between the "civilized" European nations...
It Was His Sled: The fact that the Martians are all but unstoppable by regular means but eventually get sick and die, which is usually the case in most adaptations.
The 1953 movie:
Fridge Logic: One of the first characters to be disintegrated in the 1953 film claims that they are Martians because Mars is currently at its closest approach in years. Other characters also assume this as the basis for where they come from, later on in the film. While this is true, no-one ever questions that this is only an assumption.
Narm: The Martian that Dr. Forrester and Sylvia encounter in the farmhouse. Why? Not because of its appearance but because it Screams Like a Little Girl.
Science Marches On: The movie opens with impressive Chesley Bonestelle paintings of the other planets of the Solar System except for Venus. In 1953, the nature of what lay beneath that world's clouds was unknown – deserts, swamps, and global seas of carbonated water or petroleum were all considered possibilities.
Ironically, the grossly inaccurate description of Jupiter is far more telling of Venus' surface conditions.
Interestingly, Venus - forgotten in this film - was the first planet examined by a probe, in 1962.
Technology Marches On: Back in the source novel the alien war machines were vulnerable to artillery fire and a torpedo ram, which were the most powerful weapons available at the time. In this film the aliens can survive an atom bomb blast, because otherwise they would be defeated very quickly.
Reportedly, George Pal asked a Pentagon representative how contemporary armed forces would do against the Martians from the novel. He replied in no uncertain terms it would be a Curb-Stomp Battle for humanity.