If you want to post your Google+ stream directly from Google Drive, then make sure the file's sharing settings are listed as 'Public on the web' or 'Anyone with the link'. If you see that your file is private, then your family and friends on Google+ will not be able to access it. Once you shared a file, a thumbnail preview of it will appear in your Google+ stream.
Automate backup & migration of your photos & videos with support for all top services.
Trusted by users in 125+ countries.
“Your pictures are scattered. PicBackMan helps you bring order to your digital memories.”