Symptoms:

Some customers find orienting their photos using the orientation button time consuming. 

When in the PhotoLibrary, select the catalog containing your images.  If a relatively small amount of images have an incorrect orientation, it may be faster to follow this shortcut:
        1. Hold down the "Alt" key on your keyboard.
        2. Click on the area of the photo you wish to be the top. 

For example: There is a portrait photo of your subject being displayed horizontally.  In order to rotate this image to vertical, hold the "Alt" key on your keyboard and click your mouse on your subject's face.  The image will rotate to the correct orientation.