User blog comment:TheFreddyFromThePizzaria/Equestria in Peril-The Witch Theory (By Sunlight Sparkle!)/@comment-26186871-20161117184029

Look guys, all you have to do to "respond" is leave a comment! It's that simple! If you want to critique Sunlight's theory to her, praise her, or try to add something to her theory, address your comment to Sunlight, so that I know it isn't to me. Also make it in-universe, we don't want to break the fourth wall here.

The actual theory made by her is the italics. Think of your response as, sort of sending a letter to her, in a similar way that Spike can send it.