lean in

Hi,
I've seen other threads about "lean in" but I felt it is not right for this situation. The situation is that Secretary Clinton participated in a graduation ceremony and one of the students gave a speech. She said some beautiful and meaningful things that Secretary Clinton did not expect to hear. Then she says:
“I , curious. This is not what I had expected to hear.”

In some paragraphs later she also says:

“Now her classmates were , too. They snapped their fingers instead of clapping, as Tala smiled and built to her close.”

Source: Hillary Rodham Clinton. “What Happened.”

I thought may be it means they were listening to it more carefully or something like that. What do you think?

When you lean in, you bend your upper body towards the thing you're looking at.

Do they "lean in" because of excitement? attention? what?

There is a narrow meaning of 'lean in', i.e. the physical lean. There is a popular broader sense, which encompasses the narrow (from the M-W website).

Lean in became a business motto in 2013, taken from the title of the book Lean In: Women, Work, and the Will to Lead written by Sheryl Sandberg, the Chief Operating Officer of Facebook, and Nell Scovell, a writer and Sandberg's collaborator. Sandberg's book [...]perfectly paints a picture of what Sandberg believes women need to do to move up in the business world: to press ahead, to project confidence, to "sit at the table" and physically lean in to make herself heard.

In the OP, I think the narrow meaning is there, at least initially ("I leaned in, curious.").

Sorry but I still don't get it.

RORSCHACH said:

Sorry but I still don't get it.

Is it not common in your culture to move your head closer to someone interesting by bending your upper body? That's leaning in.

RORSCHACH said:

I thought may be it means they were listening to it more carefully or something like that. What do you think?

I think you're right. She was saying things they thought were very interesting and they leaned forward naturally as they focused on her words. It's a subconscious reaction, not a conscious one to hearing something interesting and making sure you don't miss anything.