Here's why:
* Her expression softens: While she's generally cheerful and stoic, her face softens as she watches the children fly their kites, a clear sign of affection and contentment.
* She lets her guard down: Usually, she maintains a certain level of detachment, but in this scene, she fully embraces the joy of the moment, even joining in the kite flying with the children.
* She shows empathy: When Michael's kite gets stuck in a tree, she doesn't scold or dismiss his disappointment. Instead, she helps him retrieve it, showing empathy and understanding.
While not crying, Mary Poppins conveys deep emotion through her actions and subtle facial expressions. It's a moment where she allows herself to connect with the children on a deeper level, revealing a more vulnerable side of her character.