In one scene, Norma Desmond is smoking a cigarette. This is a characteristic of a film noir. This element helped develop the character of Norma Desmond. She as a character showed that she doesn't care how others think of her because she knows she is a well known actress. She believes she is above everyone and doesn't care how others think of her.
In one scene Norma Desmond kills Joe Gillis. This element is femme fatales. This movie element showed how Norma was jealous and slowly lost her mind. It also showed how much she loved Joe. She loved Joes so much that she wanted him all to herself, and when she couldnt, she killed him.
In one scene Norma Desmond goes back to Paramount studios and there is low lighting. But there is almost a spotlight on Norma. This shows how important her character is because she was a forgotten actress.