I think the author of this movie was trying to tell us that our lives are a succession of hardships and fortunate.
One day, the main character of this movie found a huge black creature was approaching her(I can't exactly say the main character is female...) when she wake up. She tried to fight it, but her power was so week to beat it and she was swallowed. She thought there was no hope to get out of the creature's stomach, but fortunately she was able to get out of there. She was reliefed, but at the same time, she noticed that a creature was coming to her again and this would wold be continued forever.
I think the author teaches us that even if you are in troubles, you can go through it , and even if you are very lucky, you shouldn't be quite proud of your luck.
