I found the following proposal while browsing /mlp/ since /b/ has been invaded by spam-bots, /m/ never updates and /s4s/ has been conquered by le master trole.
Warning: The following headcanon may melt your brain and cause cringe beyond your wildest imagination
If you haven’t gotten the implied proposal yet and aren’t currently in the corner full on fetal position, I will explain.
Obviously the top image shows Twilight’s Mom and Dad aand the bottom Twi and Trixie.
However, observe Twilight’s Dad’s cutiie mark and the cutie mark of Trixie.
Both incorporate the lunar crescent in some way shape or form. Typically, as shown by the apple family’s cutie marks all dealing with apples and the Royal Sisters having a celestial inspired marks, cutie mark design is a hereditory trait. However, such a relationship can be said to be a case of “correlation =/= causality” unless further correlation within the field of study can be established.
Now observe the color scheme of Twi’s Dad and Trixie. Their coats are somewhat similar and have similar hue ranges. Now, from study of other pony families, color duplication is not a clear indicator of being descended from each other. Moreover, as shown with the Cakes, the children only inherit one or two the hues of one of their parents (Both Pumpkin and Pound have a cream colored coat, of which, cream color is only a few saturation levels away from their fathers coat color, orange. Trixie’s coat color is only a bit lighter that Twi’s Dad’s coat color, thereby falling within the range of possible genetic descendance. This is our second case of correlation.
Third, observe the mane similarities. Trixie’s mane style has a slight wave as does her tail. Twi’s dad has a very wavy mane and tail. Often times, hair patterns can be diluted when passed from parent to child. A child can have wavy hair when their mother has curly hair and their father straight hair. In MLP, the mane and tail are analogous to hair.
Lastly, take these correlations and try to compare Trixie to Twi’s Mom and subsequently Twilight. It can be reasonably assumed that many Twilight’s mom’s genes are dominant as both Twilight and Shining Armor more resemble their mother in many ways. Both Twilight and her mom have noticeably different color streaks in their manes. Trixie has streaks, but hers are just hue different from her mane’s base color. Twi and her mom both have straight, thin manes and tails. Trixie has a full mane and tail. Twi and her mom have slight curved manes and tails whose curvatures can be assumed to be naturally constant and singular. Trixie’s mane has two countering curvatures to her mane. Twi and her mom lack a widow’s peak, despite Twi’s dad having one. Trixie has a widow’s peak.
The correlation =/= causality fallacy only holds up when when the correlation is isolated and has no other analogous relationships within the studied data. If there is at least three correlations whose individual contexts differ but whose overall fields of study coincide, correlation can no longer be assumed to not equal causality. We have three cases of Trixie bearing resemblance to Twilight’s dad and more of her not resembling Twi’s mom. “Correlation =/= causality” fallacy can be subverted in this case.
What does this mean?
Trixie could be related to a member of Twilight’s immediate family.
A possible corollary to this theory is that Twi’s dad had another foal with a mare other than Twilight’s mom. This theory would then make Trixie Twilight’s half-sister, and those two immediate family members.
This would also make all Twixie ships EXTRA ICKY-CREEPY, OMG-RIP-EYEBALLS-OUT-WITH-MELONBALLER INCEST FICS.
YOU MORONS JUST COMMITTED A WINCEST SHIP.
ARE YOU PROUD?!
That or I’m overanalyzing a cartoon, whose base priniciple is not to be 100% realistic and a fantasy. Hue