The Vivillion happens to be a bug and flying-type Pokemon which has the ability to parade over 15 different kinds of patterns on its wings. The design that you can see above, will be made available to everyone, where it is known as the “Fancy Pattern.” This would make it an exception to the rule that patterns tend to be made available to players depending on the regin that they are in.
The Pokemon Company shared, “Because of this characteristic, players around the world have been exchanging Vivillon via the GTS to collect all of the regional patterns. This newly discovered Vivillon breaks with that tradition: it will become available to Pokémon fans across the globe once the 100 millionth Pokémon is traded via the GTS. When this enormous milestone is reached, a special distribution event will take place, enabling all players of Pokemon X or Pokemon Y to receive the Fancy Pattern Vivillon wherever they are in the world!”