Alright enough with the practical vs cgi arguments, Ridley Scott will make the film his way and not what the fans want, Hell he could make most of the film cgi and i bet you lot would still watch it, i myself prefer practical effects over cgi but cgi does have its place, its used when practical effects are not sufficient in bringing something to life but i'll agree that it is at times overused.
Now lets get back to topic and talk about the set and location pics.
Right someone mentioned that one of sets looked like the Nostromo and i sort of agree, its has a similar design to passage ways and doors of the ship, kind of makes sense since its supposed to take place 30 years before Alien, there was another pic that i can't really remember because i only saw it once but it looked like the wall from the derelict not really sure though. one report i read was that the film will explain the mystery of the derelict and the space jockeys so maybe that pic was supposed to be of the derelict.