What does "flying swallows transform into dragons" mean?

Feiyan turns into a dragon: It describes a man who looks like a newborn swallow when he is not in love, but becomes as majestic as a dragon when he is in love.

1. The word "flying swallows transform into dragons" was born on June 19, 2015. It comes from the 85th chapter "Heart" of the time-travel ancient novel "Yipin Wu Zuo" written by Feng Jin, the gold medal author of Xiaoxiang Academy. Yue Qing Xi".

2. This word describes the process in which a man's "good brother" is like a newborn swallow when he is not in love, and becomes as majestic as a dragon after he is in love.