I used to work on film sets, mostly in the art department, though none of the movies I worked on were as demanding on the art department as Star Wars is. I had plenty of time to nap. Sets are full of nap times. There's so much down time and long hours that you need to learn how to sleep anywhere and everywhere if you're going to stay sane. Learn how to sleep sitting up and you pretty much have a filmmaking super power.
It's a little hard to see a picture like this of Carrie Fisher. It's just her vulnerably taking a nap. It's so peaceful and so human. It reminds me of the great loss that her death brought us, but then I remember all the joy she brought to the world. RIP Carrie. We love you.