No, it's not a photoshop job, it's a real gun (though only one exists -- it was custom made not made for sale).
The author explains the rationale:
So called "Assault Weapons Bans" such as the now expired 1994 Clinton ban and the one still in place in states such as California seek to ban rifles that our misguided legislators feel have no purpose in civilian hands. They identify "evil features" they can use to generically classify these "military style" weapons in sweeping terms. Of course these features, such as plastic pistol grips, barrel shrouds, and bayonet lugs have absolutely nothing to do with the firearms potential lethality in the real world and are merely cosmetic features. After all, it really doesn't matter what color the firearm is if it fires the same ammunition right? Well, in the "spirit" of the California Assault Weapon Ban I decided to do my best to alleviate the fears of my fellow citizens and gun-banning legislators when I put together a new AR-15 for my wife. Below is the result of my painstaking work to transform an Evil Black Rifle (EBR) into a Cute Pink RIfle (CPR). Introducing the Hello Kitty AR-15!
This rifle is 100% legal in California because it is based on an "off-list" lower receiver made by Stag Arms and has no evil features at all, instead featuring a fixed stock instead of the evil collapsible stock, a muzzle brake in place of the vile flash-hider, and a MonsterMan Grip instead of the heinous and malicious plastic pistol grip. The C Products magazine looks like a 30 round magazine body but is permanently modified to only allow 10 rounds.