When I first heard this quote, I agreed with it whole-heartedly! As a visual artist for most of my formative years (20s to mid-30s) I understood the deadline of a show. The work had to be done, or the show wouldn't open and the opening with all the wine and all your friends wouldn't be much fun. However, if I was short one piece of work, I could always frame up a sketch or a watercolor study, and the exhibition would be complete. This does not work with picture books. If there is a deadline and I am short one or two illustrations, I can't very well substitute an earlier one, nor could I suddenly have the reader turn the page from a finished color illustration to a quick pencil sketch. Picture books are complete entities-- complete "bodies of work" unto themselves and there is no substitution or quick-fixes allowed.
On the other hand, I have worked with the same editor for 16 years now and from the very beginning she has said she would rather put a book off and miss a deadline than rush it and publish a mediocre book. This philosophy has allowed me to put off a deadline more than once. In fact, I have bumped many of my books to the next list in order to do more research, or start fresh with a new approach to the text. I know this has frustrated more than one impatient author, but the final outcome is always better for the added time. And when meeting the deadline for the art, I have more often been a month or two late, but not without a lot of stress and anxiety. Usually I have all but two illustrations finished and they just aren't cooperating with the rest of the flow of the book-- or perhaps I have sent all of the art, but there is a hold-up from marketing on the cover-- (Usually I send in three to five suggestions for a cover and getting the OK to proceed depends on feed-back from my editor, the art director, marketing, etc.- this can take a very long time, especially because my deadline is usually the same as every other artist's deadline, so there is a backlog!)
My favorite time in writing or painting a book is in the beginning when deadlines are something faraway and abstract. This is my time for reverie- a time to live with the text, play with images, dream, imagine, take long walks, visit museums. It is quite the opposite from the real-life deadline time when every waking moment is the intention of finishing the work. Just thinking about it makes my heart beat faster!