What motivates the narrator to “display [her] retort” rather than to respond verbally to the man?

Assuming that you're referring to the excerpt about a woman who was criticized because she's not quitting her job because she got a baby

She felt that the man is simple minded and simply not intelligent enough  understand that she need the job to pay the bills, so rather than responding verbally, she chose to display her retort in other ways

hope this helps