explain the concept of "kitchen Sink drama" and how it applies to "Look back in anger" ?!

Look Back in Anger is considered one of the most important plays in the modern British theater. It was the first well-known example of "Kitchen Sink drama," a style of theater that explored the emotion and drama beneath the surface of ordinary domestic life. Jimmy Porter, the play's main character, became the model for the "Angry Young Man," a nickname given to an entire generation of artists and working class young men in post-World War II British society....The idea of the Kitchen Sink drama was also a revelation for British theater. The stylings of most British theater before Look Back in Anger favored Victorian dramas and comedies or stagings of classical plays. In a general sense, the Victorian plays dealt mostly with polite themes from the late 19th and early 20th century upper ruling class. In contrast, Osborne's play depicted the raw emotions and living conditions of the working class. This style of theater was given the name "Kitchen Sink" because of its focus on the interior domestic and emotional lives of ordinary people. In the case of Look Back in Anger, the kitchen is literally a part of the set.