If you are done customizing your theme and need quick feedback, you can share it without even have to leave the builder. All it takes is an email and you are good to go.
- Inside the builder, click on your gravatar and select "My Customizations";
- Open the three dots menu, next to the save icon, and click on "Share";
- Now all you need to do is enter the email of the person(s) you want to share your customization with, write your message and click "Send".
And that's it. Three cheers for productivity!