One critic, writing in 1943, described
the Shelter Drawings in terms of natural phenomena. He compared the strange colours, scratchy lines and pitted surfaces to 'lichen of grey rock, the coloured texture of weather-worn stone, the fiery black and red of igneous formations of burning coal'.
Such associations between Moore's shelterers and nature supported a general propaganda message that within the British people lived an indomitable,
almost elemental force which would prevail whatever the threat.