"The actual producing, mixing, and mastering is hard work, harder than what I do"

Mandy Moore is referring to the process of creating music. The actual producing, mixing, and learning of a song is a tough and time-consuming procedure. It requires a great deal of skill and understanding to develop a quality track. Moore is indicating that the work she does is not as challenging as the work that enters into producing, mixing, and mastering a song. She is most likely describing her own work as a star, vocalist, and songwriter, which is certainly not as hard as the technical aspects of producing music. Moore is highlighting the hard work and dedication that goes into producing, blending, and mastering a song, and is most likely trying to give credit to those who operate in the music market.