牛皮燈籠

Etymology
First part of a xiehouyu. The second part could be:
 * 1) 點不明 (Mandarin) / 點極都唔明 (Cantonese) – cannot be lit / cannot be made to understand
 * 2) 肚裡亮 – bright inside / understand in one's mind

Idiom

 * 1) stupid or stubborn person; someone who does not understand or listen to others
 * 2) someone who understands in one's mind