The technique is a palindromic couplet.
Palindromic couplets change the position of the verses or reverse the order of the verses, so that the couplets can maintain complete meaning and smooth reading when reading forward or backward.
Palindromic couplet is a rhetorical technique in couplets, which is more demanding in conception and creation. Through the clever use of language and vocabulary, the couplets can maintain the same meaning when they are read front and back, giving people a unique aesthetic experience.