This picture is editing a manuscript. After the first draft of the book is written, you go through and edit the book to find mistakes and to make it even better. Through the writing career, tons of red marks will be made to the book to improve it.
I love this so much! I'd suggest if you can't take a walk (say in winter) walk around your house with your ear buds in, and pace. The music will help stimulate your walking pace and increase blood flow to your brain to keep you thinking! I do this all the time and it helps! ☺