Twilight had planned to visit Sunset Shimmer and her friends over in the other world for a nice, quiet weekend, away from all the worries and problems associated with being a Princess of Equestria. Unfortunately, things rarely go as planned. After an accident cuts her off from Equestria, Twilight finds herself stuck in the human world until the gateway between the two worlds can be fixed. Which wouldn't normally be a problem...
...If she wasn't still a pony.
Sunset's Little Twilight provides examples of:
- Animals Not to Scale: Despite being a pony, Twilight is described as being no bigger than a small dog or a large cat.
- Broken Glass Penalty: Courtesy of Rainbow Dash and Rarity, the front window of Applejack's house ends up smashed by a wayward soccer ball. Twilight manages to (mostly) repair it with considerable magic effort on her part, though.
- Call-Back: Just before entering the Mirror Portal, Twilight warns Spike not to overdo it on ice cream again.
- Call-Forward: While remarking on the idea of magic in the human world, Sunset mentions if it would be possible to create a device to track it.
- Can't Believe I Said That: Sunset thinks this after she realized she just used the phrase "Hold your horses".
- Cool Bike: Sunset's preferred mode of transportation is a motorcycle.
- Cooldown Hug: When Twilight begins to freak out over possibly being stuck in the human world for an unknown amount of time, Fluttershy calms her down with one of these.
- Cuteness Overload: Fluttershy's reaction to the miniature Twilight.
- Fun Size: Twilight arrives from Equestria no bigger than a cat.
- Hidden in Plain Sight: Rarity's plan to hide Twilight hinges on this idea, with help from an Embarrassing Animal Suit.
- It Was with You All Along: Late in the story, Flash's father mentions an incident where his wife spent an hour looking for her glasses, only to find them in her pocket.
- Luminescent Blush: Fluttershy tries to hide her blushing face when Twilight innocently asks what a bra is.
- My Eyes Are Up Here: Sunset's response when Rainbow gets a peek up her shirt.
- Not a Morning Person: Pinkie Pie, of all people. She shambles into the kitchen like a zombie in her pursuit of coffee.
- Oh, Crap!: Sunset's reaction to Twilight's Sneeze of Doom is "Oh, Horseapples..."
- Punctuated! For! Emphasis!: Upon seeing the full extent of Twilight's Embarrassing Animal Suit, Rainbow Dash is ready to bust a gut. Twilight's response?Twilight: Don't. Say. Anything.
- Ridiculously Cute Critter: The typical reaction to the tiny Twilight.
- Scrabble Babble: Subverted - four of the girls play Scrabble at Applejack's house at one point (Pinkie and Applejack are playing Go Fish in the same room), and both Sunset and Twilight play real words that they have to explain - Sunset's is "Alicorn", which she explains by pointing to Twilight, and Twilight's is "zax", which Rainbow Dash doesn't believe is real even after Applejack says she used one a while back. It's soon confirmed to be a type of cutting tool.
- Simple Solution Won't Work: When Twilight frets over the fact that the portal's mana resonation coil broke and she had used her last one in an experiment, Rainbow Dash half-heartedly asks why she can't just remove it and use it anyway. Twilight retorts that the coil is a delicate piece of equipment that synchronizes with whatever it's installed into, and that removing one and placing it in another machine could have catastrophic results.
- Sneeze of Doom: Just as Sunset's about to tell the others about Twilight's current state, Twilight sneezes from inside Sunset's backpack, blowing her cover.
- The Mirror Shows Your True Self: Combined with Mirror Scare, Sunset briefly sees her pony self staring back at her in the bathroom mirror. When she looks again, it's been replaced by her normal reflection.
- Tranquil Fury: Applejack's reaction after Rainbow Dash and Rarity accidentally smash her window.
- Your Magic's No Good Here: Despite still being a pony, Twilight is unable to use magic at first. Even after she's able to get around this, the magic is so different from what she's used to, coupled with her smaller size, that even simple spells become much more difficult, and some even impossible without fear of injury.