The Rock is a largely metaphorical piece painted in the Precisionist style begun near the end of WW2 and finished 4 years later. After years of work it was completed in 1948. Blume's work often is an amalgamation of experiences recontextualized - not "real" but many realities, perceptions, and ideas mixed together to create a coherent piece.

This painting is almost a Rube Goldberg-esque assemblage of old (on the right) to new (on the left). In the middle, a landmark is shattered and the ground it sits upon being rendered for materials in a new building on the left. A woman in the middle, at first glance appears to be desperately worshiping the rock, but upon closer inspection, she is actually clawing at the earth beneath it, drawing out more stone slabs to continue building, making the centerpiece unstable. Nearly everyone else in the painting is a continuation of these efforts, converting raw materials into a new building, except the man on the right, burning down what's left of a house that appears to have been in the German bombing of London.

https://magazine.artland.com/art-movements-precisionism/#:~:text=Precisionist%20artworks%20are%20characterised%20by,famous%20name%20associated%20with%20Precisionism.

https://bigthink.com/culture-religion/how-peter-blume-painted-his-personal-reality-of-hope/