When a photo is added it will be automatically resized to fit to the height of the location that it was placed and then the center of the image will be used. If you would like to use a specific part of the photo you can click the Crop button and you can use the Crop Dialog to crop a specific area of the photo.
If the photo is larger than the cell you wish to place it you can move the selection block around using your mouse and you can grab the handles and resize the selection area to capture what you want to capture. As you resize the selection area it will keep the correct aspect ratio so that it will fit correctly in the area you want to place it.
Cropping definitions will be moved if you move the picture from one cell to another only if the cells are the same size. Any time a picture is dropped onto a cell the cropping definition will be cleared so the new photo can be managed.
When you crop an image any flip/rotation commands are executed first and these are reflected when you are using the cropping dialog.