Literally 'small shoes', but almost always used in the idiom
穿小鞋 (chuān xiǎoxié) — 'to make someone wear small shoes', i.e. give them a hard time. Folk explanation: in old China a mother-in-law would gift her new daughter-in-law deliberately undersized shoes; today it refers to any covert harassment from a superior, especially a boss using bureaucratic power to punish a subordinate.