You can now share anything on your Google Plus stream when on Gmail.com. You need not go to Google Plus to share a photo, text or a link.
1. When you’re logged into gmail, using a your browser, towards the top-right corner, you will notice a Share box near your Google Plus notification icon.
2. Just click on it.
3. You will now get a small window where you can type and share anything you like into the Google Plus stream.