What is the function of a music video?

• One of the functions of this music video  is the representation of the artist, Jessie J. Jessie J portrays a 'bad girl' image from her previous song lyrics and music videos such as 'Do it like a dude.' In this video the child character of Jessie J is being rebellious and going against her teachers which supports Jessie J's bad girl image. 
• Music videos are also used to make the song memorable, when people hear 'Who's laughing now' they will think of the music video.
• Establishes pop genre through the music video