The Metrics Inspector gives you fine control over the size and positioning of elements on the page.
You can view and adjust the size of the element on the page. See Resizing Elements for more information.
Some elements (such as images) should retain their aspect ratio when being resized so that the image does not become distorted. You can allow free-sizing of these elements by unchecking this box. Most elements can be freely resized.
Images are often scaled down to fit on the page. You can restore the image to its original size by clicking on this button. This is very useful when working with screenshots.
You can view and adjust the position of the element on the page. The position shown here is the position of the top-left corner of the unrotated element. In other words, if the element is rotated, its top-left corner will be rotated away from the position shown here.
You can view and adjust the rotation of an element on the page. The element rotates around its center.
The last two controls allow you to flip images around their vertical and horizontal axes for mirror effects.