How does Kathryn Forbes use imagery in Mama's Bank Account?

Imagery:

I would contemplate the rusty drainpipe that ascended the gloomy Karboe house next door. Only of course it wasn't a drainpipe, it was a trellis of ivy - and by such means would the young prince come to rescue the beautiful young princess held captive in the high tower.

I could gaze into our dreary empty backyard. Then the red geraniums that Mama had set out would become rare, exotic blossoms - and I could see a great white charger pawing at the broken pieces of pavement.