Big MAC means two things: that this LBR is cheap or some other form of derogatory meaning and 2) that she is "big" on wearing way too much MAC brand makeup all the time.
Massie describes her as a "chunky goth girl who wears too much MAC makeup."
Bratfest at Tiffany'sEdit
It is raining outside the overflow trailers. Big MAC is standing in the rain with the other LBRs. Here is a quote from Big MAC herself, "I have mascara in my eyes. It burns!" Then the mascara runs down her face and she tries wiping it only making matters worse. She is described as looking like an "oil painting."