These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: My Little Pony Friendship Is Magic S 3 E 3 Too Many Pinkie Pies
And this one. "Pinkie's gone and broke [sic] the fourth wall again! She's multiplied herself to unimaginable numbers, and now Twilight Sparkle is the only one who can stop the rampaging horde of Party Ponies. Don't feel bad about putting them down though: They are only semi-intelligent copies of the real Pinkie Pie, who is nowhere to be found."
Also, fans had originally guessed that the Mane Six would clone themselves in order to better help with the wedding preparations in A CanterlotWedding based on the clone filled trailer. This was before we learned anything about the Changelings.
A good chunk of the fandom seems to have decided that since Fancy Pants was in Ponyville, this obviously means he was doing something with Rarity that cannot be shown on children's television. Supporting this, Rarity was dressed to the nines for no clear reason, and it seems odd that a Canterlot noble seems to be just hanging out in Ponyville....
The way Noteworthy and Golden Harvest were smiling and waving at each other from their windows at one point could also be seen as something of a background pony Ship Tease.
Take That, Scrappy!: One of the Pinkie clones turns her face into a pony's face from G3 only to get zapped by Twilight Sparkle. This is even more noticeable where, in a case of Manipulative Editing, an ad with that clip has Rarity and Fluttershy react to the face with horror.