...the symbolism of Lebeau goes much deeper: in Lebeau it involves the vanitas motif, which in art is often depicted by a (grinning) skull. The skull confronts the viewer with the transience of life and his own mortality. Lebeau deftly portrays the essence of the most important performance of Die Haghespelers [a theater group] in 1914: Hamlet by William Shakespeare. "To be or not to be, that is the question," the grinning skull behind our mask. See also the Hamlet poster which Lebeau made in the same period. In 1920, Lebeau used this idea once again for his cover design for the collection of poems of life and death on August Heyting (1879-1949). The cover of the book shows the same skull and the title page contains seven individual masks with different facial expressions and a grinning skull in the middle. (https://anno1900.nl/2013/05/22/to-be-or-not-to-be-volgens-chris-lebeau/)