The first two pictures of the shredded paper were taken with depth to field. The very first one has a shallow depth of field of around f4 and the focus on the center. This created an image of surrounding blur, with a few strips of textbook paper shown in focus in the center. The second shot was taken with a large depth to field of about f15, making all of the confetti in focus. I personally like the the first one the best because it makes an interesting, more complex shot that accentuates the words as if to portray a message. You use shallow depth to field in order to hi-light certain objects within a field of blur, whereas large depth of field is used when you want the overall image, making everything in focus. The chair photo on the top right is a great example of depth, showing foreground middle ground and background. It starts with the bars of one chair being zoomed to frame the shot and then allows your eyes to move into the piece and view the other chair in the middle and a bag/box in the far back. This picture is actually showing a lot more space than it looks; a whole room to be exact.