I think Giger might have picked this idea up from Chris Foss with whom he worked on Dune and Alien. Foss had a narrow gauge railway in his backyard with which he was obsessed. Giger naturally put his own spin on his version:
There are two clips of this unused landscape shot in the 2003 three-hours documentary - along with the Ray Caple (matte painting and live-action shot) of the Derelict's three openings. This also unused shot would have illustrated the immense size of the Derelict in relation to the three astronauts - something the comic book adaptation did extremely well (the double-page spread).
One more of Roy Carple's matte paintings was used for a shot showing the three crew members walking on the planet's surface that was cut. Apologies if this has been posted before.
Interesting... in the one I posted you can see the two orifices and floor are real while only the arm is painting. Note the four crew members. Obviously painted on glass with the film being projected through from behind.