Inside the studio

That sounds very familiar..

Another common thing artists will experience is suddenly having a trailer shot due. A trailer company is hired to cut a trailer from the film’s current edit. They work separately from the director who is busy working with the editor. They may cut several trailers, and then show them to the director and studio for feedback. Once everyone agrees on a few cuts, the studio will test the trailer for a small audience and the one that scores the highest across the desired demographic will be the trailer that is selected for finalization. It happens so quickly that even the internal teams can barely keep up. The shots in the trailer which are visual effects shot have to go back to the vendor for completion. Sometimes they can’t complete the shot and they say to send it to another vendor for trailer version only, and sometimes they beef up hours and get it done and charge a slight overage or rush cost. That’s when you the artist are called, usually late into the process, and you find out the shot has a trailer version due soon and you need to work overtime. It’s a compliment that the trailer company chose the shot, but it’s also a drag because it might not look as great as you want for the final film. All that matters is that it’s good enough for the trailer at that point.

There's a lot more at vfxlaw and well worth a read if you want to know what's going on "inside the studio".