Google has a little treat in store for you the next time you sign into Gmail or Inbox and want to share an image over Hangouts. Just drag and drop the file into the chat window to attach it to your message. A circle will pop up with the words Drop image to attach written underneath.
The picture won't send automatically, so you have time to add a message or change your mind. Also, you can't send multiple images at once.
The functionality is already live, so if things aren't working for you, try refreshing your tab or restarting the Chrome app. And if you aren't a fan of dragging and dropping, you can also copy and paste. That should work too now.