Wow, guys. No need to freaking go into a fight because of something so obvious in all the business these days.
These trailer materials are some times month apart from creation. All latest movies teaser, first and second Trailer and then the final film have huge differences. Especially the CGI.
As an explanation, why the Xeno looks not only different because of the updated lightning of the scene, is the level of displacement mapping (look it here up:
https://en.wikipedia.org/wiki/Displacement_mapping)
The first renders have to be done quick and high settings of displacement are heavy on render time. Even my models differ by settings from half an hour per frame up to 4 h! Of course a house like MPC has huge render farms and can facilitate data we can´t even imagine, but this process takes just huge amount of time and marketing is doing it´s own thing along that.
Other reason as well, sometimes they even change the render engine. So the first footage might have been on a more light level (some even use Unreal Engine and similar) and the end render in final quality is Render Man. Huge difference of appearance.
For example, Guardians of the Galaxy use two different CGI studios to do Rocket Raccoon and Groot. As well they used different render engines. Trick is the end comp and grading.
And for the guys wondering why the ship changed, this is full CG scene. No ship, no sky, no Alien. Full out of the tin. And there will be plenty of those.
And now let´s enjoy the last 45 days of waiting time
