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 S2 E9: "Sweet and Elite"
In this episode, Rarity learns that she shouldn't be ashamed of where she comes from. But what about putting the priorities of your friends first? Isn't that a more fitting moral?
Twilight threw that moral out the window when she told Rarity to go talk to the Canterlot ponies. Most friends would prefer that their friend do something that will help them get connected rather than a birthday party.
Besides, acknowledging your roots (hometown and friends, in this case) is an important lesson, because it makes up a large part of who you are. The only reason Rarity does lie is that she's compromising that.
Were the mane six socially clueless at the Garden Party, or were they serving alcoholic drinks at Twilight's party and had gotten slightly inebriated?Maybe that's why Spike wasn't present…
Did Fancypants recognize Twilight Sparkle for who she was? He gives a mysterious wink when he refers to her as "this lovely young filly from Ponyville..." If this is true, he may even know a little bit about her personality — particularly that she dislikes special treatment and that she wouldn't appreciate him announcing her identity.
For that matter, is Fancypants helping further Rarity's social career from sheer good nature and altruism, or is he just enjoying the way she gets under the skin of obnoxious social-climbers like Jet Set and Upper Crust?
Crazy Awesome: If the "Party Cannon" doesn't make Pinkie Pie this, then nothing ever will.
Ensemble Darkhorse: This episode introduced several new minor and background ponies. Fancypants has become quite popular in the fandom, and his unnamed female companion spawned a bunch of fanart within a day of the episode airing.
There's a funny case with Wonderbolt Fleetfoot. A few days before this episode aired, someone created an OC Stand In out of an Off Model Wonderbolt that appears briefly in "The Best Night Ever", giving her the name Echo. The premise of a blind Wonderbolt was popular enough to get fanart within days... and in this episode "Echo" returns, gets the name Fleetfoot, and wins the race. Said blog adopted it as Echo's surname, and now she's one of the most popular Wonderbolts.
Spoiled by the Format: "Hearth's Warming Eve" originally aired before "Family Appreciation Day" and "Baby Cakes", so its plot synopsis was known prior to this episode's airing. As a result, the synopsis that mentioned the *six* friends going to Canterlot to do a play suggested that Rarity would choose her friends over her important business connections.
Strawman Has a Point: The Canterlot Elite are depicted as smug elitists for treating the ponies from Ponyville as boorish hicks. In addition to ruining the Grand Galloping Gala (the highest profile national annual party), Rarity's friends crash and trash the Canterlot Garden Party (the second highest profile national annual party), making one wonder if the reputation for being boorish hicks is at least somewhat deserved. Indeed, for the Gala, Celestia deliberately invited the main characters in hopes of "livening up" the party, and afterwards claims it was the best one in a long time BECAUSE they screwed up a party which is, for her, exceedingly boring, further adding fuel to the fire.