You have it all wrong...

Based on the teaser and trailer... It looks like the "invitation" may be in fact a warning or trap. Similar to how in Alien the derelict ship sent out a beacon that was presumed later to be a warning. Now what if we know it was a lure. Also, the invitation has a picture of a very large humanoid presumably the SJ which means it's a species that predates us and not just David evolved. When Shaw says we were wrong it's highly likely that she is referring to the invitation. What if the SJ's are destroyers of worlds and are in no way shape or form benevolent or spreading life. When a species finds them they "collect" their DNA to reuse as they see fit and then deploy a ship to destroy their home world. Think like a roaming galactic collector that harvests life for it's own purposes and then kills the source. The fact we look like them but smaller ie: the giant head would lead me to believe we are related somehow but just how I am not sure. Also, the ALIEN forming in the wall could be a security system and the first actual Xeno that we know and love. When a life form walks in it's scanned and a Xeno based on that life form is created. Once activated it seeks out life and reproduces to eradicate every living thing. The URNs or Ampules may have nothing to do with Xeno's but the SJ's just designed the Xeno to reporduce in a similar manner. Like an architect that uses a certain style to all his buildings. Also, at the end of the trailer shaw is on the ground and it looks like a human size SJ is standing over her. What if that is David and the mutation on his android body turned him into a pseudo SJ while maybe it turns humans and others into monsters or some kind of Xeno.... Thoughts?