How does David McCullough use imagery in The Great Bridge?

Imagery:

"The massive, freestanding masonry tower rising at the edge of Brooklyn was still the only part of the bridge conspicuously on display. Through the whole of that spring, as charges of fraud and jobbery filled the papers and Brooklyn gossiped of bridge scandals, work on the tower had proceeded exactly according to schedule and the immense granite shaft was looked upon popularly as an irrefutable affirmation of all that had been promised and anticipated over the past several years. One look at something like this was enough to restore a person's faith in what man could do and to make crooked bookkeeping and the life seem both terribly petty and no more than a temporary nuisance."