Tentative Guesses

After Di Tou turned his head to see the bird-man, he could no longer take his eyes away, and his entire body refused to listen to him. Instead, like he was in a cutscene, he could only watch as the bird-man sang its song repeatedly and watch as the expressions shifted from anguished to resentful to hopeful to hateful. A plethora of emotions Di Tou didn't think he could even see in one person, much less a bird.

But listening to the figure repeat itself over and over, although Di Tou couldn't help but feel fearful, then somewhat confused, in the end, all he could feel was numb. Over and over, like a broken repeater, the bird-man continued to sing, and although he was creeped out and initially was in a panicked state due to his lack of control and ability to escape, seeing that nothing was happening, Di Tou naturally relaxed after a while.

It had to be said that humans really were resilient creatures and could get used to just about any situation.