The "Add To" dialog provides a mechanism to add selected picture(s) from the current location to albums or groups. If the "Add To" button is dimmed, then you do not have any pictures selected. To add pictures to albums or groups using this dialog, you must:
You can also add Albums or Groups from this screen (if they don't already exist).
To Add a new album, press the "Add Album" button. It will prompt you for the album information.
To Add a new group, select the location you wish to add the group and press the "Add Group" button. It will add it as a "child" group of the selected group. For example, if the "Add Group" button is pressed in the screenshot displayed, it will add a group underneath the "Vacations" album. You can add groups to albums or other groups.