Aluminum Christmas Trees: Some viewers may be surprised to learn that tail extensions for horses are a very real thing.
Broken Base: Fans are divided on the scene where the CMC are shunned by the whole town once their identities get found out somehow, whether everypony's reaction believable or not, and more so, whether it was justified or hurtful.
A popular plot for a Fix Fic of the episode usualy has Rainbow Dash, Twilight Sparkle, Spike, Rarity, Applejack, and Big Mac called out by other characters. In the case of Twilight Sparkle and Spike, Princess Celestia is the one calling them out, and in the case of Applejack and Big Mac, Granny Smith is the one calling them out.
Another popular plot is the CMC running away due to guilt.
Fanon Discontinuity: Some fans like to pretend that this episode never happened because of its mean-spirited nature and how the rest of Ponyville came across as hypocrites for enjoying the gossip column and then getting mad when their reputations were personally affected by it.
Spike reaches down Rainbow Dash's throat to retrieve one of the cucumber slices she swallowed and puts it on his eye.
Also, Snips' and Snails' shaved behinds!
Unintentionally Unsympathetic: Word of God is that the residents of Ponyville shunning of CMC was meant to be justified as "them trying to avoid talking to them because anything they say could end up in print out of context." But they admit that nuance wasn't effectively conveyed in the final product, leading it to be viewed as undeservedly cruel. Plus, the fact that they themselves gossiped about someone before just adds in to the trope and makes the CMC embarrassing them seem more like a long overdue penalty.
The Woobie: While it is easy to blame the CMC for all the public humiliation they caused, you can't help but feel for the three poor fillies when they're shunned by the entire town, including their own friends and relatives, after word gets out about them being Gabby Gums.