By default, banner photos will be inserted with the entire photo showing. You may want to cut out a part of the photo. For example, if there is a lot of sky showing in a photo you may want to remove some of the sky.
To reposition the photo, just place your mouse cursor over the photo and drag to move it around. If your mouse is close to the page heading, you might need to move the mouse cursor higher, so it is away from the heading.
You can also use some preset positions, (top aligned, middle aligned and bottom aligned) to make positioning the photo easier.
To use a preset position
On the top menu that sits over the top of the banner photo, click the Banner menu
Under Alignment, select either Top, Middle or Bottom
You can drag to reposition the photo at any time, cancelling out a preset position