Prometheus: The Head Room

Leading from 

Prometheus: The Space Jockey / The Engineers
and
Gutalin's homage to the Tron MCP face

a) Having the head room room idea

When Arthur Max took some of the motif's from Giger's derelict corridor design  ribs and created columns that were almost plant like in nature and then gave the layout to the illustrators who developed that into drawings, Ridley looked at it and said, "Can we have a statue, a sculpture or something iconic in the middle that celebrates the Engineers?". He also wanted the place to have the feel of a cathedral with something quasi-religious about it.

b) Steve Messing perception of the headroom
Steve Messing also talked about being involved in the design work, he perceived the chamber as a ceremonial room. Julian Caldrow worked on the details for this environment and created the set drawings. 

c) See:  Giger-esque relief in the ampule room

d) Who exactly were these engineers though?  
The idea was that the Engineers race are interplanetary visitors who from time to time over the millenias have come to Earth to give us upgrades - mentally and physically, there was also the idea that they engineered humanoid life forms throughout the galaxy.

e) How would they celebrate themselves? 
They came up with the idea of a giant head and how it was part of the culture of the Engineers to build these things. So they appear to be associated loosely with the idea of Earths ancient head building culture. The centrepiece of a chamber that would come to be known at the Ampule Room, with the plant like columns that was set at Pinewood was a 32 foot tall monolithic head, which can be glimpsed in posters for the film. This was practically built by Arthur Max's team.

the ampule room

1. Arthur Max: I TOOK some of the motif's from the Giger Corridor - type of ribs and we created columns that were almost plant like in nature, and then gave that layout to the illustrators who developed that into drawings, then Ridley looked at it and said ,"Can we have a statue, a sculpture or something iconic in the middle that celebrates the Engineers?" The idea being that the Engineers, playing the role of God in the universe, have visited Earth many times over the millennia and given mankind genetic upgrades, both physical and intellectual. How would they celebrate themselves? So we came up with the idea of a giant head. (Prometheus, the art of the film, p111. ) 
2. The idea there is that it’s part of the culture of the Engineers. This race of interplanetary visitors who have given us upgrades – mentally and physically – over the millennium. (Source: spotlightreport.net, 18th April 2012)
3. Ben Mortimer: Was there a particular set piece from the film that you really hang your hat on?
   
   
   Arthur Max: Ridley wanted one of the key sets, which you see on most of the posters, the giant head, ampoule chamber, he wanted it to have a feel of a cathedral, something quasi religious about it. (www.heyuguys.com 1st June, 2012)