I felt curious about it and clicked the site's About link and read this:
FREQUENTLY ASKED QUESTIONS:
Q. I have a great idea for a cartoon. Will you draw it for me?
I enjoy the straightforwardness in the answer. You just can't say you don't understand or took it wrong. Easy. Simple. Perfect.
It also reminded me of a Rework essay: "Draw a line in the sand". I find Nina Paley's answer draws a pretty clear line in the sand.