Hi Lili,
Understanding men better works best when you avoid reading too much into something that they say or do.
Sometimes with men, the simplest explanation is actually the right one.
When a guy changes the sound of his voice like it was done in the video, it is typically to make his audience feel less intimidated by their situation.
In other words, the guy just wants the audience or the person that he is addressing to avoid overthinking their particular situation and look at it with more of a simple and lighthearted perspective.