Daily Chinese Idiom Guessing Game
To change only the appearance or superficial aspects of something while keeping the substance unchanged; to disguise or reform superficially.
原指人的容貌发生了改变。现多比喻只改外表和形式，内容实质不变。
唐·寒山《诗三百三首》第二一四首改头换面孔，不离旧时人。”
The company rebranded with a new logo and website, but it was just a 改头换面 attempt that didn't fix the core issues.