[She's perceptive, good. He nods in approval, slowly walking about the area. She's right, in the sense that walls are large expanses, and that carving walls takes effort.]

So someone wanted to make a statement. In Roman times, back on my Earth, people would paint graffiti all over the city to express their anger or impatience. Statues and walls had carved words to commemorate something or someone. [Bruce glances upward, following the text to the top of the monolith.] This wasn't anything ordinary.

[He could easily finish the train of thought, but he lets it be. He wants to see what this young woman could figure out from context clues alone. Though he's assuming everything here operates the same as Earth, it's at least a better basis than simply guessing.]