If someone becomes famous because of a well-publicised event, people may want to know their full story—what led to that event, what really happened, the aftermath, and their feelings and views about it all. In the case of Malala Yousafzai, she was shot by the Taliban for speaking publicly about the right for all girls to go to school.
In this snippet, Malala uses the events leading up to that moment as a teaser for her memoir. It starts with a snapshot of normal life and slowly adds hints of what we know is to come (even if you don’t know, you get the feeling something bad is going to happen).
Short sentences and line breaks build the suspense. Just before the moment, it cuts the narrative. The ultimate teaser!