From “Reason of Sleep” 

This artwork is made by a technique called photogram, in which objects are placed directly on photographic paper and then exposed to light. The cover bears the French text, "Raison du sommeil" (reason of sleep). This mysterious title was probably inspired by the famous print by the Spanish painter Francisco de Goya, "The Sleep of Reason Produces Monsters" (1799). As in English, the French word raison can mean the power to think or a cause, so if you were to turn “sleep of reason” in the Goya title around you would get “reason of sleep.” The work was created in the period leading up to the Sino-Japanese War (1937) and World War II. In the context of such difficult times, Ei-Kyu may be encouraging people to sneak into the world of sleep and let their imaginations run free.
(KURAYA Mika)

*You can see other works from this series.