I think 'shipping' in that context would be finishing a novel, short story, screenplay or whatever. To the point where you've proofread it for typos. Even if

I think 'shipping' in that context would be finishing a novel, short story, screenplay or whatever. To the point where you've proofread it for typos. Even if you decide it's not good enough to show anyone. It's the act of completing one project and starting another project that you will also complete. "Not shipping" would be writing down ideas in your story journal or outlining forever, writing the first page or first chapter or the first act, deciding the idea is going nowhere, and going back to the drawing board, and starting over again and again and again.