Natasha turns around when she notices other people looking and sees a flash mob on the platform. She takes a few phone pictures and wonders why she's not, as she usually would be, thinking about why those dancers were dancing instead of doing something more productive. She reasons that if Daniel were here, he'd suggest that the dancers were trying to bring a little bit of wonder to everyday life.
When Natasha is able to actually put herself in Daniel's mindset and understand that the dancers did serve a purpose, it reinforces the idea that both are learning from each other. Further, it shows that Natasha specifically is learning that passionate pursuits like dancing aren't just silly.