Easter egg: There's a short documentary on the DVD about the subliminal message cartoon that triggers River. To get to it, put the cursor on play on the main screen. From there, push the left button once. Now the cursor will be on the right side of the screen in the middle (up and down). Press enter.
Serenity (2005)
1 easter egg
Directed by: Joss Whedon
Starring: Chiwetel Ejiofor, Alan Tudyk, Nathan Fillion, Adam Baldwin, Morena Baccarin, Gina Torres, Summer Glau, Jewel Staite
Continuity mistake: When the crew are in the cockpit talking about Miranda, Jayne is in the background holding his head with his left hand. 5-6 shots later he is holding it with his right hand. On the cast commentary of the DVD, Adam Baldwin says that he did this on purpose "just to mess with continuity". (01:03:35)
Trivia: Despite being well-known for killing-off his characters, director Joss Whedon originally didn't plan to kill-of the characters Wash or Shepherd Book. He only chose to because the actors were unable to contractually commit to any potential sequels at the time due to possible scheduling conflicts. The studio refused to make the film without all cast members locked down for a sequel in advance, so killing them off was the practical solution.
Question: Why is River bare-foot so often, especially on a ship that has a lot of metal flooring?
Answer: The reason is that Summer Glau had severe tendinitis and arthritis in her feet and wearing shoes was painful for her.
I actually got to ask Summer this at Galaxy Con. She said that being barefoot helped her focus on becoming her character.
Answer: She has several mental disorders, presumably she finds shoes confining or uncomfortable. It's notable that when she does have footwear it's almost always heavy calf high boots, instead of slippers or more comfortable shoes.
Grumpy Scot
To add; She likes to dance, and being barefoot it's easier to move around.
lionhead
Something I always wondered is when she goes on the heist barefoot at the beginning of the film, none of the other characters seem to notice or care that she's in bare feet. Even her brother, Simon, didn't try to get her to wear shoes.