To move an image within a photo box, either click on the Crop button in the second-level toolbar or select and double-click on the image to activate the Crop tool. If the selection box turns blue, that means that the Crop tool is in image mode and the photo can be moved within the photo box. (If the selection box is yellow, you are only able to move the photo box, not the image within the photo box.)
Once the Crop tool is in image mode, indicated by the blue selection box, click on the image and drag it within the photo box.
Once you have the image placed where you want it, click outside the image to leave it in position.