Google Photos: Turn on Auto Enhance and Auto Awesome
To take full advantage of Google's "dark room" for your photos, be sure your settings are up to date in your Google Account.
Go to: https://www.google.com/settings/plus?hl=en
And click Google+ on the left. Then go down to the Auto Enhance section and choose Normal or High. I chose normal. You can always go to High on a photo by photo basis later when you are reviewing your photos.
Also, be sure Auto Awesome is checked. This way, you'll get extra photos "gifted" to you when Google can make something cool with them like an animated gif.
More details about Auto Enhance are here: https://support.google.com/plus/answer/1053729?p=photos_auto_enhance&hl=en&authuser=0&rd=1
And it should be noted that the Photo Editor does not currently work in Windows 8.1. No sure why as I thought these features were part of Chrome and web standards but I guess there is some kind of hook in the OS as well. Not sure they're right, it doesn't work.