Leatherface's Backstory Explained

In Texas Chain Saw Massacre, Leatherface doesn't just wear one mask, he actually switches between a couple different ones, depending on the scene. Why does he change his mask? Is it just a random habit, or is there a deeper meaning? According to the late Gunnar Hansen, the actor who originally played Leatherface, the masks were not just creepy accessories. They were actually the only way Leatherface could really express himself. 

"The reason [Leatherface] wore a mask, according to Tobe and Kim, was that the mask really determined his personality. Who he wanted to be that day determined what mask he put on," Hansen said. "So when Drayton comes home with Sally, Leatherface is wearing the 'Old Lady Mask' and he's wearing an apron and carrying a wooden spoon, he wants to be domestic, helpful in the kitchen. At dinner he wears a different face, the 'Pretty Woman,' which has makeup."