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 8 Just For Sidekicks
Spike's treatment in this episode. Some found it funny, others found it unintentionally sad, the latter due to him not being invited to help welcome the inspector.
Fans are even divided on Zecora's role in this episode. Granted, her intentions for donating one of Spike's gems to charity were good, but it's hard for fans to decide whether it was an all-around good deed to get Spike to think straight or a major Disproportionate Retribution (considering how some even interpret the way Zecora went about it and compare Spike's greed in this episode to his greed in "Secret Of My Excess").
Screw Loose, previously seen as an asylum patient during the end of "Read it and Weep". Her short cameo in the background of this episode showed her in a house. Fans of the show were very happy to see her again and also happy that she apparently no longer thinks she's a dog.
The skinny nerdy pony from "Putting Your Hoof Down" is back as well, and running his own potions business as well.
A little Girl Scout (Filly Scout?) pony, seen only briefly when Zecora took one of Spike's gems and donated it to charity. The bronies have already embraced her and named her "Tag Along", after a brand of Girl Scout cookie.
The Scrappy: Angel, who wavers as one to the fanbase, was more or less confirmed as an In-Universe example for the rest of the pets, who hate his bad attitude as much as Spike does..
What an Idiot: Spike's whole dilemma is essentially caused because he can't control himself when it comes to eating gems. Facepalms are a natural reaction to this.
The Woobie: Basically everything that happens to Spike this episode. Though some of his antics with the pets are funny and he eventually learned that he should have been caring for the pets like he promised instead of his cake, it wasn't a good day for the baby dragon. He was not invited to the Crystal Kingdom despite being one of it's saviors and he gets more sad as he has to quickly give up all the gems he got just to get him out of trouble.