Compared to the existential horrors of war and human fickleness, nature is a source of comfort and a refuge for both Woolf and the narrator. In particular, tree imagery becomes a reservoir of calm for the narrator in the midst of her otherwise scattered, at times nihilistic thoughts:
For years and years [trees] grow, without paying any attention to us, in meadows, in forests, and by the side of rivers - all things one likes to think about. The cows swish their tails beneath them on hot afternoons; they paint rivers so green that when a moorhen dives one expects to see its feathers all green when it comes up again.
Juxtaposed with the transiency of human existence, Woolf's tree-centric imagery allows the reader to imagine something more permanent—something unyielding to the slog of time and indecision. Compared to the anxiety latent in earlier passages, in which the narrator speculates about the mark and life's transiency, the tree imagery in this passage is distinctly soothing. Though humans may bring about change in the world—not all of it good—it comforts the narrator to know that some things, like trees, remain constant.
Woolf uses indeterminate imagery, culminating in mysterious "barrows," to describe the narrator's search to understand the mark:
In certain lights that mark on the wall seems actually to project from the wall. Nor is it entirely circular. I cannot be sure, but it seems to cast a perceptible shadow, suggesting that if I ran my finger down that strip of wall it would, at a certain point, mount and descend a small tumulus, a smooth tumulus like those barrows on the South Downs which are, they say, either tombs or camps.
The narrator realizes that the mark may be three-dimensional, projecting outward from the wall. The word "tumulus" is typically used to define an ancient burial mound or grave; yet, in this image conjured up by the narrator, the purpose of the tumulus is indeterminate. The English people do not know how these barrows were used by the ancient peoples who created them; similarly, the narrator is unable to identify the mark on the wall or its original purpose. Woolf's use of these ambiguous barrows to represent the mark, which in turn represents the indeterminacy of life, is skillful. Imagery often has the greatest impact when figurative language mirrors literal or concrete arguments. In this instance, Woolf's philosophical argument about life is embedded in "The Mark on the Wall" on many levels, both literal, as in the indeterminate mark, and metaphorical, as in the unknowability of life's meaning.
