If I upload a photo to Facebook then also upload photo to Google+ specific with album options.
1. To Address: Use Google Picasa 'Upload photos by email' address.Find it/create it here: https://picasaweb.google.com/lh/settings 2. Subject: Specify Picasa/Google+ album by putting name of album in email Subject. 'Facebook' in my example. The Album must already exist in your Google Albums. Create an album by uploading a random photo and renaming the Album to 'Facebook'. **Privacy settings for Google+ re-share is determined my Album privacy settings.** Edit advanced settings for specific album here: https://picasaweb.google.com/lh/myphotos?noredirect=1. Select album, then at the bottom right, Add Circles/People to share with and check notify these people when photos are uploaded to this album. If you do not specify an album that is already in your Google Photos, then the default upload location will be Google's private 'Drop Box' Album which you can re-share from. *Note this has nothing to do with the ‘DropBox’ the App.*