abake
Rex Tremendae Majestatis
Actually it is, and you're the one who doesn't understand his art.
They are all the "Engineers" designed to be the beings who interacted with the creature. They are a mirror of the company representing the fates of the humans who encounter them.
The Jockey in Alien is a trucker whose cargo goes out of control foreshadowing the fate of our heroes. Nostromo crew = Space Truckers
Prometheus they are scientists, whose experiments get out of control and kill them. Prometheus crew = Scientests
The poltergeist pic is an unused piece of Giger's art. Ridley Scott used many unused HR Giger designs in Prometheus including his DUNE dome pyramid design among a myriad of other things.
Really?
Care to explain how you came to this conclusion?
Because you can clearly see that the creatures in the (unused) mural have elongated heads, whereas the others don't...
And anyway, these are concept designs, not used in the final film. So how are they proof of anything?
Yes, some of them were made for the film, but so where a lot of designs by Cobb and others, and that doesn't mean the three-legged green bug is in any way part of the Alien universe...
The final Giger Alien on the movie is pretty different from his own designs. But the one in the MOVIE is the alien, not his designs. You have to judge what's in the movie.
I have to say, this discussion is amusing.