What does "Potemkin façade" mean?

A showy or imposing facade made to divert attention from an embarrassing fact or condition.

In 1787, a Russian statesman and former lover of Catherine the Great named Grigory Aleksandrovich Potemkin hastily erected a number of phony "mobile villages" along the banks of the Dnieper River ... Accurate or not, the terms "Potemkin village" and "Potemkin facade" (or simply the word "Potemkin") have stuck.