The pre in preview means that the students were able to see the movie before it actually came out.
It really depends on the movie. For instance, in Apollo 13, scenes were shoot aboard a Boeing KC-135 or the Vomit Comet. It is a NASA's refueling tanker plane for Zero G training. Astronauts wanna-be would fly up in the plane and experience a free fall.
Answer:
The phrase helps give the passage a casual and humorous tone.
