The Layout pane displays the controls that are in the view. When you select a control, or an element of a control, it will be selected in the view editor window and the properties of the selected item can be edited.
In addition, you can reorganize controls by dragging a control to another location in the Layout pane. When a control is moved, its new position will be reflected in the view editor's window.
You can expand or collapse controls in the Layout pane. When expanded, you can see any controls that are within another control, as well as the elements that make up more complex controls, like tables. Clicking on a control will expand it, but it will not expand all of the other controls and elements within it. To expand the contents of a control, right-click on the control and select Expand All. To collapse the contents of a control, right-click on the control and select Collapse All.