Cameron (Director/Writer) uses the structure of the ship according to the class that boards it. The first-class and second-class passengers were literally riding above the 3rd class in more than one way. The ship would have been impossible to build without the income from the third class ticket holders, because there were so many of them. This set up was through the eye of the Functional Theorist.
The first class was also allowed to board their automobiles, since they were highly rewarded with such items. The bourgeoisie were white collar, as in Doctors, Lawyers, Government Politicians, Scientists and the religious. They are typically the class that uses their knowledge for their income. They paid the most for their tickets to board, which gives them prestige and influence over the proletariat. This is a typical indication of the social stratification in the way of the order theorist.
When Mr. Cal Dawson met Captain Smith and invited him into the Bridge to give him a tour. They also went to the smoke room and drank mixed drinks, talking of business and vacations on the boat deck. They were on the same class level and communicated well.
Rose and her mother were dressed in their elegant evening gowns. They tucked and primped their clothes and hair to look good. These are symbols of wealth along with the jewelry, dresses, hats, and dispositions. Needing to look exquisite for dinner and frolicking on the Promenade Deck as the upper class do. When the first class section went to their formal dining area they descended down a grand staircase that shown a glass skyline high above them. The grand staircase was made of solid oak, with carved panels all the way around it. At the foot of the staircase was a Cherub light and also a very distinctive wood carved clock was elegantly placed in the center of the stairway. These things are rewards to the prestigious community of the ship.
The ruling class also had the special honors and rewarded with a Turkish bath.