What is Cinema?

The author makes some interesting points about art in the book. He talks about how in the past, people looked for realistic, true to form depictions of life and the world in paintings, sculptures, and other art forms. This limited artistic expression in art because artists would have to create strictly within the boundaries of reality in order to satisfy that hunger for realism. He then talks about how cameras, and the art forms associated with them, have come to satisfy the hunger for realism that many people seek in art. Since consumers of art could now get their fix of realism from photographs or film, this freed artists in other art forms from their boundaries and allowed for more stylized and out-of-the-box creations.
As someone who consumes art in today's world, I have definitely observed an emphasis of realism placed on film and other camera art forms that is not necessarily placed on other forms as heavily. Painters can create really abstract works that don't exactly resemble anything that exists. Cartoonists can create very exaggerated and unrealistic pictures. But filmmakers and photographers are more commonly held to the standard of being ultra realistic.