Mrs Lovett is in love with Sweeney Todd, who is on a killing spree, and turns his victims into pies to sell to the people of London. When Mrs. Lovett sings about her love for Todd, she sings, "I'll go to the ends of the earth for you, I'll do anything you want me to do." This tells us that Lovett would do anything for Todd and throughout the film he mentions how he turned bodies into cakes to impress Todd. To sell the cakes, she knew her shop would have to be renovated and reopened, which she did. So we can infer that Mrs. Lovett was motivated by the dream of marrying Sweeney Todd to improve her pie shop and sell pies to the man. This tells us that Mrs. Lovett is motivated by her dream of improving her baking business. Burton wanted us to understand that people can be motivated to do terrible things to achieve their dreams with the example of how Mrs. Lovett sold cakes to men to impress