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 S1 E4 "Applebuck Season"
Jerkass Woobie: Applejack's stubbornness and arrogance lead her to work herself into a disoriented wreck, causing a lot of collateral damage in the process. By the end of the episode, her strain and symptoms become unsettlingly realistic (if still humorous) and you end up feeling for her when she reaches the point where she doesn't just cave in to Twilight's offer but outright begs for it.
Applejack going "Oooooo!" has become rather popular.
Never Live It Down: Big Macintosh is often drawn in fanart with a straw in his mouth, despite never doing it after this episode. It probably helps that he's unusually chatty here.
Squick: Spike finds the "baked bads" delicious. He even picks them from the trash.
Woobie: Subtle and (most probably) unintentional, but right at the end of the episode Applejack says to the other main cast: "But the real award is having you five as my friends." Right at that moment Spike walks into the frame, and you would expect Applejack to acknowledge him too... but she says nothing.