水晶塔

shuǐjīngtǎ ㄕㄨㄟˇ ㄐㄧㄥ ㄊㄚˇ

    • something beautiful but of no practical use

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
crystal tower
Meaning
Something beautiful but of no practical use. Mildly critical.

Sources