Editor's note: CNN Contributor Bob Greene is a best-selling author whose books include "Late Edition: A Love Story" and "And You Know You Should Be Glad: A True Story of Lifelong Friendship."
(CNN) -- It is one of the most famous exchanges of dialogue in the history of movies.
And, in a way few people foresaw, it is becoming literal.
The movie was 1950's "Sunset Boulevard," directed by Billy Wilder. A struggling screenwriter, played by William Holden, has inadvertently ended up in the home of a forgotten silent-movies star, played by Gloria Swanson.
He says: "I know your face. ... You're Norma Desmond. You used to be in silent pictures. You used to be big."
And she says: "I am big. It's the pictures that got small."
Fast-forward to today and to a bitter controversy unfolding in the movie industry. The major studios want to make some feature films available for home viewing much sooner than the customary delay of four months or so. They want to digitally deliver, at a premium price, movies that may still be in theaters to home television sets two months after the movies open.
Movie-theater operators are furious. They see this as being financially disastrous. They worry that if people know they can see top-tier movies with A-list stars in their homes so soon after the movies are released, they won't bother going to the theaters. Prominent directors, including James Cameron, Michael Bay and Peter Jackson, have weighed in on the side of the theater owners.
In April they signed a letter to support a system "that encourages movie lovers to see films in the optimum, and most profitable, exhibition arena: the movie theaters of America."
The fight between the studios and the theater operators is, at its core, about money. But for the rest of us, there may be an unintended consequence. The very sense of what it means to be a movie star could be on the verge of being forever altered.
A movie star is unlike any other kind of celebrity. Movie stars have long been the biggest stars in the world; few actors or actresses, given the choice, elect to work in television if they have the stuff to be a leading man or leading lady in the movies. Being a movie star is the peak of the mountain.
Much of this derives from the magnitude of the image on the movie-theater screen. At the movies, the stars we watch are, literally, larger than life. On a television screen, even the sizable ones, the actors are smaller than life -- smaller than us.
Does it matter to the public? We're about to find out. Already, people are becoming accustomed to watching movies on their computer screens, on their cell phones, on their tablets. The movies, including the ones with the most famous and highly paid stars, are becoming portable, and because of that, they are shrinking.
If feature films that are intended for movie-theater viewing become routinely available in homes while they're still in theaters, will it change the way we feel about movie stars? Will the distinction between movie stars and every other kind of star evaporate, when everyone we watch is the same size?
I thought I'd ask an old friend who has given more thought to these kinds of questions than just about anyone else. When we first met, we were pounding away on Royal manual typewriters within earshot of each other, and he was just beginning to review movies playing in theaters that had one giant screen in one enormous auditorium, often with multiple balconies soaring to a gorgeously painted ceiling.
"Yes, this is happening," Roger Ebert responded. "Stardom depends on the big screen. Now that some people actually watch movies on cell phones, stardom has been demystified."
That's the key: the mystification, the myth-making, of the huge screen in the movie theater. It has been that way since the days of Humphrey Bogart and John Wayne, of Clark Gable and Gary Cooper, of Marilyn Monroe and Grace Kelly. Maybe it started to go away when the theaters were sliced up into mini-theaters, with 12 or 22 movies playing in all the different rooms. Perhaps the sense of moment, of grandeur, of a night out at the movies began to fade about the same time as the disappearance of the battalions of flashlight-wielding ushers with gold-braid epaulets on their uniform shoulders.
Yet movie stars continued, and continue, to be movie stars, separate from everyone else. Will that remain, as we become more and more conditioned to watching feature films on the same small screens where we watch television dramas and comedies? On the same computer and phone screens where we read our e-mail?
In the 1980s, I was checking out of a hotel in New York, and in the lobby I turned to leave and the person next to me was Cary Grant.
He was 80. He hadn't made a film since the mid-1960s. He was wearing a perfectly cut dark blue suit, and he looked...
Well, he looked like what he was. He looked like a movie star.
Everyone in the lobby tried not to stare, and everyone failed. He was clearly waiting for someone. A woman arrived, and he said to her: "Are you ready, then?" The two of them left.
Leaving the rest of us to ponder what had just happened.
The person standing nearest to me -- a man I had never met -- summed it up about as well as it could be summed up.
"Damn," he said. "Cary Grant."
There will continue to be name-above-the-title stars as the screens continue to shrink, and there will continue to be men and women who make their livings solely in feature films. But the mystification that Ebert referred to -- the magic that washes over us at we sit in the dark, looking at those oversized people on those oversized screens -- will that be as strong?
"I am big," said the woman on the screen. "It's the pictures that got small."
Damn. Cary Grant.
The opinions expressed in this commentary are solely those of Bob Greene.