Image imported from derpibooru 
Original Description:
 
This flag is a love letter to Shakespearicles that i & some friends has worked on.
 
This is the flag & banner of the 2nd Equestrian Age or Neo Equestria if you want.  
Neo Equestra Is Rule by Queen Flurry Heart & King Nova Sparkle, descriptions on the 2 & their relationship can be found here. https://derpibooru.org/images/2825566?q=princess+flurry+heart_2C+oc3Aprince+nova+sparkle
 
The Yin part of the symbol represents King Nova Sparkle. The Yang Part of the symbol represents Queen Flurry Heart.
 
The Stripes in the background represents the both the King’s & the Queens parents.  
The Upper stripe represents Twily.  
The Middle stripe represents Shiny.  
The Lower stripe represents Cady.  
These 3 colors of these 3 stripes are taken from the 3’s manes & tails.
 
This flag in for a fanfic universe, from a fanfic called Cat’s Cradle.