In this first picture, we can see that the books are not completely sharp, just parts of them. The titles are not entirely in focus, so it gives less informations. With the books not completely in focus, the shallow depth of field gives more importance to certain words of the titles of the books.
In this second picture, there is more depth of field than in the first one, but it's still not entirely sharp. The background is still a little bit blurry. We can see more of the titles of the books, so unlike the first photo, the focus is more on the books themselves rather than just parts of them.
In this last picture, the depth of filed is definitely larger than the first two. The background is sharper and the books are completely in focus. The feeling, I would say is the same as the second picture. The focus is still on the books.
In this first portrait, with the shallow depth of field, he focus is entirely on her. It also makes the background less busy than it is.
In this second portrait, the background is definitely sharper than in the first picture. This time, the focus is not really only on her anymore, the background comes part of the "what to look at" aspect too. Also, with a deeper depth of field, the picture is busier than the first portrait.