How does Hugh Leonard use imagery in Da?

Imagery can be found in the playwright's stage directions.

The action starts in May 1968. Charlie, overcoat on, is at the kitchen table, sorting letters, family papers, old photos, etc., into two piles. He finds one paper of interest and puts on his glasses to examine it. He then goes to the range and pours boiling water from the kettle into a teapot. He then picks up the teapot as Oliver comes to the door. He is Charlie's age—early forties. His clothes are too neat for him to be prosperous; youthful bouncy step, handkerchief exploding from his breast pocket. He sees that the door is ajar. He knocks all the same.