She proceeded to talk about the benefits of talking about one's mental health with others and how people can support their friends by listening.
"It helps us all to talk about our mental health: what to say and who to talk to when we have feelings that are too big to manage on our own," she said, "and how to listen and help if one of our friends is finding things difficult. Sometimes it's just a simple conversation that can make things better."
The film starred a group of young students who are depicted as fingerprints. Just as how everyone's fingerprint is different, each student experienced different emotions at different times and manages them in unique ways.
The film differentiated between "small feelings" that people experience every day (e.g. happiness, anger) and "big feelings" that don't go away and inhibit the way people live their daily lives.
One character in particular, Jay, struggled to manage her big feelings on her own.
"Am I in the jungle? Am I in the sea? My head is going crazy. Will you come and save me?" Jay said in the film. "My tummy hurts. I can't get to sleep at night. I can't concentrate at school. It feels like I have a volcano inside of me getting hotter and hotter."
However, Jay struggled to find the right person to talk to and what to say. The video provided tips on how to ask for help, how to be a good listener when someone asks for help and how children can talk to adults when they need further guidance.
Jay ended up confiding in her friend Jack who talks to their swim coach about Jay's feelings. Jay started to get the help she needs and began to feel better.
The Duchess of Cambridge has worked on other mental health initiatives with her husband Prince William and his brother Prince Harry as part of their Heads Together campaign.