Sir Walter Allward’s inspiration for the Vimy Memorial came to him in a dream, in which, he said, dead soldiers “rose in masses, filed silently by and entered the fight to aid the living. So vivid was this impression, that when I awoke it stayed with me for months. Without the dead we were helpless. So I have tried to show this in this monument to Canada’s fallen, what we owed them and we will forever owe them.” Captain William Longstaff’s “Vimy Ridge” artwork (circa 1930-1939) combines Allward’s inspiration with the resulting striking monument.
There doesn’t seem to be a high-res version online that I can find :(