Asteroid city is a film about a play with scenes that are about the same play broadcast as a TV program with the camera pulled back and forth to reveal the stage setting back in the day. A play within a play if you like but mediated by differrent technologies.
The play is a rough pastiche of the Roswell UFO incident and the subsequent military panic and narrative control. It's many other things too but the basic themes are UFO/Aliens/Technology and the effects these have on the (gifted) children and their parents who appear in the play and movie.
It's not complimentary about the parents who are only motivated by their childrens scientific achievements while neglecting their emotional needs. The children too are distant and robotic in manner.
Most people wont like this movie but I did as Wes Anderson could have made this a silent movie and the visual perfection would keep me going. I hope Wes reads this post as every review I watched concluded differently.