His voluminous body (due to a metabolic disorder) contrasted strikingly with his normally discrete way of acting. His low voice was often loaded with undertones of kindness, pity or scorn. With effortless ease he appeared both as warm-hearted philanthropists and arrogant cynics, depressed underdogs as well as more social beings.
One of his special gifts was the ability to perform “the colossus with feet of clay”, apparently solid and superior natures - both sympathetic and unsympathetic - who are dissolved. Among his best-known serious performances are his mean-cultivated informer type in Afsporet (1942 - Derailed); his leader af a children’s home, a sadist with shattered nerves in the social film Kampen mod uretten (1949 - The Struggle Against Injustice) and his two versatile portraits of alcoholics who are destroyed in Ta’ hvad du vil ha’ (1947 – Take What You Want) and Café Paradis (1951). Among his many comedian roles must be noted his amiable ham actor in Biskoppen (1944 – The Bishop). In his later years he was a regular participant in the so-called “Morten Korch films” (based upon the regional novels of a very popular Danish light literate) often placed as the fatherly friend of the hero and his serial role as a widower with children in the popular Far til fire (The Father of Four) films.
Apart from froma few Swedish movies, Schønberg made only Danish films. In the late 1940' he was offered the role of Martin Luther in Hollywood but he turned it down. Schønberg was recognised as a film star throughout Europe, but his popularity rested on his audience appeal as the Danish everyman.
Schønberg was known for his almost manic industriousness. In 1949 he took part in every Danish film of that year and during the last six years of his life (1949–1955) he appeared in almost 60 films. He was an active public figure, appearing at the opening of exhibitions, and freely providing the press with interviews about his ideas and projects. Schønberg, with his volatile temper and often transient commitment to projects, felt best suited to working in films rather than theater. However, he occasionally performed on stage and during his last years he was director of the "Circus Revue".
His drive, hard work and temperament, combined with a problem with obesity, contributed to an early death at the age of 52. He was afflicted with a pneumonia in May of 1955 and remained bed-ridden until he died on September 24, 1955.