Fluttershy Flutters now looked like a Margaret Thatcher, if Margaret Thatcher were a pony. She flew over the blockade of Ponyville and towards the Crystal Empire. Once she reached the Crystal Empire, she entered the mirror portal and became a human. As a human, she looked like Margaret Thatcher. That's what you get for eating a weasel, Flutters.
Once in the human world (Scottsdale, Arizona, specifically), she traveled to the gun store. She had a special mission.