Google wants to help make it easy for you to add photos while using Gmail on your phone with a new “Insert Photo” button. Gmail product manager Thijs van As said in a blog post this is meant to ease the sharing process a bit for mobile users. You can even resize images in Gmail. “When you click the button, you’ll instantly access all the photos that are backed up from your mobile devices starting with the most recent.”
However, it also forces users to use Auto Backup through Google+. This feature is meant to back up your photos and videos directly on the social network.