Today, I noticed that:
Turnabout Storm, Part 1, published in October 2011, contains a joke about the protagonist’s spikey haircut looking like a “porcupine”;
Turnabout Storm, Part 3: Twilight, published in September 2012, covers the same timespan as the previous episode (Part 3: Phoenix) but reveals different events by following different characters who go to different places.
and then I saw Games Ponies Play, published in February 2013, which:
contains a scene in which Rarity briefly turns Twilight Sparkle’s mane into a spikey shape and says: “Imagine her mane turned into a porcupine.”
covers the same timespan as the previous episode (Just for Sidekicks) but reveals different events by following different characters who go to different places.
Is Games Ponies Play a shoutout to Turnabout Storm?