From now any image inserted into a post using the IMAGE button in the FORMATTING menu will allow the image to be displayed in a lightbox when clicked. Here are the steps to make that happen:
1. Press The Image Button In The Formatting Menu
2. Put the URL of the picture you want to display under the INFO tab

3. Put the same URL used above in the URL field in under the LINK tab.

For best results, set the width of your pics no larger than 375 px.
That's it! Enjoy!