Why does Zhang Zhiming send text messages in turn?

In order to create a hidden and interesting expression.

In the movie "Love of a Pure Son", Zhang Zhiming's anti-texting behavior is not to convey a definite message, but to create a hidden and interesting expression, so that the short message doesn't look like expressing love or missing, but a special flirting code. This plot in the movie was deeply remembered by netizens and began to imitate it in daily life, presenting some combinations of letters and numbers in a special way as a way to express thoughts and love.