What makes the presentation of Chapter 15 in The Grapes of Wrath cinematic?

Chapter 15 can be considered cinematic because it provides an overview of the social situation during the Great Depression, and the exhibition of charity to the migrants appeals to the human interest factor.

One of the intercalary chapters of The Grapes of Wrath, Chapter 15 presents a scenario of one of the restaurants along Route 66, the route that crosses the country. Route 66 is the path of the wealthy on vacation and the people in flight as they head for the promised land of California, where there is hope and the possibility of a new beginning.

Certainly, a film could be made of the various people who enter the short-order restaurants near the gas stations along Route 66. Inside these restaurants is a tableau of the people who compose America of the 1930s. There are the wealthy who travel in their luxury cars and stop only for a cold drink that they complain is not cold:

The woman will use six paper napkins and drop them on the floor. The man will choke and try to put the blame on Mae [the waitress].

The truck drivers, however, are generous. They leave a quarter for their coffee and pie, which gives a dime for the waitress.

In one scenario, one of the many migrant cars stops: a 1926 Nash, loaded with pans and mattresses. The man asks Mae, the waitress, if he may have some water for his radiator; after he fills the radiator, his boys drink from the hose. Inside the cafe, he humbly asks Mae if he may buy a ten-cent loaf of bread, but Mae says they do not sell loaves; however, they have sandwiches for sale. Embarrassed, the man explains that he can only afford the bread. Al, the boss, tells her to sell him a loaf. Mae pulls a loaf out, telling the man that it costs fifteen cents, but Al orders her to give it to him for ten cents. When the two little boys, dressed only in overalls, longingly eye the peppermint sticks, the man, who has pulled out a penny with his dime, asks how much they cost. Mae then becomes generous, saying they are "two for a penny." The little boys heave a happy sigh and clutch the peppermints to their sides as they walk out, then leap into the car and burrow out of sight as their father starts the old car and makes his way onto the highway and heads West.

One of the truck drivers named Bill says, "Them wasn't two-for-a-cent candy."
"What's that to you?" Mae said fiercely.
"We got to get goin'" said the other man. "We're droppin' time."
Bill put a coin on the counter and the other man looked at it and reached again and put down a coin.

As they say good-bye, Mae calls to them, "You got change." "You go to hell," calls back Bill, and they climb into the truck. Mae calls Al's name softly. He looks as Mae points to the coins, and goes back to his grill without a word. "Truck drivers," Mae says reverently.

From the random acts of charity that are extended to them as they travel, the migrants regain faith in humanity and life, as do the waitress and owner of the short-order restaurants along Route 66.