Since segue means to move from one thing to another seamlessly, (literally from one piece of music to another, but figuratively used of other things) I imagine they intend this to mean that you both move into and then out of the writing process with ease.
If so, it's a poor use; segue refers to the way in which the transition from one thing to the next is seemless as observed by another. This doesn't really make much sense in terms of the writing process. (Except perhaps for those days in which the transition from doing things like answering questions on EL&U to getting some writing done was indeed seemless, because one never actually got any writing done).
I think they are perhaps thinking of the more general idea of "ease" and applying segue to that, but that seems far too much a stretch to be felicitous.