How does Alice McDermott use imagery in Charming Billy?

Example of Imagery:

"Of the (let's face it) half dozen or so basic versions of the Irish physiognomy, they had two of them: Billy thin-faced with black hair and pale blue eyes behind his rimless glasses; Dennis with broad cheeks, eternally flushed, and dark eyes and fair hair that had only begun to thin under his combat helmet, somewhere, he claimed, in northern France. One every inch the poet or the scholar, the other a perfect young cop or barman. The aesthete priest and the jolly chaplain."