When Pokemon X & Y was released, a dedicated website for international players went live online, with the url www.pokemonxy.com.
However, with the website now redirecting to a generic page, the images might become lost to time.
As of writing, Japan's XY-individual site is still online (http://www.pokemon.co.jp/ex/xy/), but at some point it might go offline, so the images are archived as well. Additionally, certain XY-limited images were also included, for archiving sake.
The style of artwork I use for the Event Gallery was inspired by this splashed-style.
Apparently, the splash artwork in the background is slightly different between international and japanese versions.
International ver. VS Japanese ver.
These images can be downloaded together here.