Shortened from the chengyu
画饼充饥, derived per 《
三国志·
魏志·
卢毓传》:
魏明帝 told official
卢毓 that picking officials by reputation alone is like
画地作饼,
不可啖也 ('drawing a pancake on the ground — you can't actually eat it'). The two-character
画饼 later became the standalone verb used in modern office slang.