To burnish the image of someone or something means to improve their image.
例句
The European Parliament badly needs a president who can burnish its image.欧洲议会急需一位能改善其声望的主席。
英汉词典释义
vt.
擦亮(金属等);磨光
the gleam of burnished gold黄金的光泽The sun, round as an orange and orange as hot-weather moon, balances on the horizon, burnishes the silvered winter wood.太阳圆得像个橘子,颜色也是暑天月亮那样的橘红,支在地平线上,装点着银色的冬日树林。