ADDED 4/11: More here
ADDED 5/12: Latest here "Space Jockeys are Galactic Police"
Above image is one of the most intriguing yet from 'Prometheus'. I went on at some length regarding plot possibilities after the last batch of stills and, while I still like my conclusions, this new photo gives reason for pause.
Don't continue if you're not into speculation about plot. If anything I conjure up turns out to be true it will be a woofing spoiler. So, stop now.
Okay. if you're still reading, the new pic is curious. As I posited, the Space Jockey (SJ) were, from appearances (read: what I extracted through brute force from tenuous indications), on their way to Earth to colonize the planet when an accident or malfunction caused the release of an alien (as seen in the movie 'Alien') which killed the crew of the horseshoe ship (HS).
(This is predicated on the presumption the HS in the trailers for 'Prometheus' is the same one found crashed on its side in 'Alien'. If this isn't the case it blows most of my theory out of the water).
So then. The crew of the Prometheus go aboard the HS (or, perhaps, feasibly, into the tunnels system built into the mountain shown in the holographic map) and they find the above image in the ceiling. What does that mean? Why would such an image be on the HS?
The painting bears a resemblance to our own religious imagery. Also, it's up high, in the ceiling. Placement and style suggest it's a focal point of reverence. That the SJ worshiped us, or in lieu of that, held us in the highest regard, however, is a tough sell. If the HS was filled with a cargo of parasitic beasts that would gestate inside a human and burst out when ready killing the host in the process, it seems very unlikely the SJ revered us. It would seem much more likely they were on their way to Earth to exterminate the human race. If not, why bring thousands of pods containing a weaponized organism? (If the pods don't contain this it would change everything, but we have to utilize what we know from 'Alien'. Otherwise, there's no point in speculation).
Another argument against the possibility the painting holds humans in reverence is that such images serve no practical purpose on any spacecraft (with one notable exception).
Then, if the painting does not depict a human as an object of reverence, what does it depict? My guess would be it shows a being (who represents and entire race) submitting to conquest. The figure's head is bowed in submission and he averts his gaze to the side in deference to a superior being not seen in the photo. The image is but one of several painted along the edge of the ceiling, each showing another species which has been destroyed by the SJ. This is a gallery of conquered races and the conqueror, the Space Jockeys, is/are pictured in the center of the ceiling, directly above any viewer who might enter the room, gloating over the vanquished.
Let's take an even closer look at the person in the painting.
I've optimized contrast and density to make things clear.
What is that circled on the man's chest? It has a long body, perhaps four legs on either side, and a head with eyes. That would be one of the weaponized organisms in the pods in the cargo hold of the horseshoe ship.
Pictured is a trophy gallery on board a ship heading to Earth to take over the planet. This would make the SJ an arrogant race of conquerors who take over any planet with an oxygen-rich atmosphere, killing all its intelligent inhabitants, who glorify the process in paintings. In fact, the SJ are so full of themselves the paintings are standard-issue on all invasion craft, put there to inspire the crew on their long journey.
In the movie, in this scene, (if the above is true), the person shining the flashlight would look around the ceiling. There, he or she would see paintings of other beings from other planets the Space Jockeys have conquered, all with their heads bowed in submission (or to look at the nasty thing on their body about to kill them), and their arms open in acceptance of their fate.
The SJ, it turns out, are brutal and have no concern or respect for other life forms whatsoever, and the only thing that stopped them from reaching Earth was an accident or malfunction. You have to wonder what that sets up story-wise and whether another HS will appear in a sequel.
Apologies if I ruined the story (assuming I got it right), but you were warned.