Click that to enter Pan mode, to drag the view. The first button, the four arrows, is the Pan control. There are buttons on the main toolbar for panning and zooming too: If you don't have a middle mouse button, you can hold the Space bar on your keyboard down instead - you'll see the mouse cursor change to a hand, and then you can grab and drag the view with the left mouse button. To pan the view, sliding the window around, press and hold the middle mouse button and move the mouse. You can also use the - and + keys in the upper-right of the keyboard to zoom. If you have a touch-pad (like a Mac) using a two-finger swipe up or down does the same thing. Scrolling the mouse wheel will zoom in or out from the location of the mouse - you can simply point at something with the mouse and scroll the mouse wheel to zoom in on that point. The Edit Window, the center of the main display, can be moved around and zoomed with the mouse to help you focus on different parts of your design.
Numeric Edits - size, position, orientation
