Featured Picture Boxes 1.0.2 brought along a new feature, the ability to specify a custom title. You do this by using Custom Fields on a post. The following is an example.
Edit post and make sure you can see Custom Fields (you may need to check it in screen options)
Then go down to custom fields and enter your new title under ‘fpb_title’. The first time you do this you will need to click ‘enter new’ rather than selecting from the dropdown. Your New title will display whenever that post is used in a Featured Picture Box instead of the original.