How the speaker uses her own background

Jacinda Ardern uses her personal background in her “Harvard Commencement Speech– Democracy, disinformation and kindness” to build ethos, as well as to better convey the message. 

Firstly, she uses her personal background to express the idea that people with different views can exist peacefully together:

I was a Mormon in a town where the dominant religions were Catholic, Anglican and Rugby. I was a woman ...