The sender of the speech is Michelle Obama. She was the first lady of america in 2009 to 2017, she was also the first african american to become first lady.
Michelle Obama is married to Barack Obama, who was the president of the United States while she was first lady. Michelle Obama is a graduate of Princeton University and Harvard Law School, and today she is a lawyer.
Michelle launched the "let's move" program in 2010 to help obese children, with a lot of support from her husband. Today Michelle Obama is 57 years old and is still active .
She also uses herself and her own experiences to support that what she is saying is not just empty words but that there is a meaning to it and that they can actually lead somewhere.
The tone of the speech is cheerful but still serious, she starts the speech by saying "Isn't it exciting " which gives a feeling she is also very excited to talk about it and ready to come out with the message.
While the speech is cheerful, one can also sense the seriousness of it. She makes it clear to the public that those she says are important in terms of repeating the things that are important.