Snowflake
Namgoong sees a snowflake float onto the train while helping the revolt move forward. The image of the snowflake shows us very plainly that the world outside is no longer in such a deep Ice Age, and is beginning to thaw. This one tiny snowflake represents a sense of possibility and hope that Nam uses to forge ahead with the revolutionaries.
Polar Bear
At the end of the film, Yona and Timmy wander out into the snowy wilderness outside the now-destroyed train. Wrapped in large fur jackets, they look more ancient than futuristic, and not long after disembarking from the train, they see a large polar bear, a sign that there is life in the outside world, an image that gives them hope that they will be able to find a way to live beyond Snowpiercer.
Close-Up
Bong Joon-ho uses a close up of Curtis while he is telling Namgoong about his having to resort to eating other people to survive in the tail of the train. In a close frame, we see the emotions of regret and despair passing across Curtis' face, which shows us the pain he feels for having had to resort to such horrible means of staying alive.
Wilford
Wilford is talked about a lot throughout the film, and seems like he must be a fearsome and impressive figure. He is almost like the Wizard of Oz or another such famous and revered figure—never seen but deeply feared and respected. Thus, it comes as somewhat of a surprise when Wilford just turns out to be a normal and polite gray-haired white man in a silk robe, eating steak at a nice table. Wilford looks like a retired businessman, a man of leisure and pleasure, not an intimidating or awe-inspiring king. There is a contrast between people's expectation of what Wilford might be like and the rather everyday image of the man himself.
