Nightmare Sequence in Hugo (Specifically)

Specifically in Hugo's nightmare sequence, the train signifies the early introduction of film to society. In Hugo they discuss how the audience was at first frightened by the idea of an incoming train on the screen; as they began to understand how film can work. The thought that a screen can place one at a whole other setting from which they already were was fascinating.
The nightmare sequence connects to two other scenes in the movie. One connection is how Hugo dreams of finding the heart shaped key, and the second being him transforming in the automaton. The finding of the key in the dream connects to how Hugo really finds it through its owner which happens to be his friend. Hugo makes a discovery with how the key first belonged to George. M; thinking that he may have an idea of what happened to his deceased father. The second connection of Hugo transfroming into the automaton makes a connection with Hugo's life and the loss of his father. This broken automaton is the only memory Hugo has left of his father. Through the film I understand that Hugo has dedicated his life to fixing this machine to find an answer to a message that his father may have left behind. Him transforming into the automaton signifies how this machine has taken over his life and who he has become as a person.
During the nightmare sequence there were key cinematic moments, an example is when tracking was used while the navigator realized that Hugo was on the track. I believe they decided to show a closeup of the train wheels to let the audience know how a machine can work and how it can fail. I feel that there are some people who see no wrong with machines and technology, but the truth is that almost anything can go wrong. I thought of this during this scene; first there was a closeup of the train wheels as it was functioning correctly, then there was another closeup as the wheels were trying to be stopped but couldn't.