The captured nominal compound is formed by two antonymous adjectives.The meaning of this noun is a quality whose bipolar extremes are signaled by the Ttwo adjectival constituents. Here are some illustrations:
好坏 ‘good-bad=quality’
大小 ‘big-small=size’
真假 ‘true-false=truthfulness’
Reference
Li, C. N., & Thompson, S. A. (1989). Mandarin Chinese: A functional reference grammar (Vol. 3). Univ of California Press.