The only difference is the method by which the image and copyright release is provided to you. Digital Images are preferred by most customers. With a Digital Image you will be notified by email with instructions to access the image. Once claimed, the Digital Image is saved in your account indefinitely and can be accessed as often as you want. A My Digital Portrait CD is a CD that contains the image and copyright release. By purchasing a CD the image won't be automatically saved in your account.
Both the Digital Image and CD will include the same high-resolution images with copyright release.