In Japan, it's been popular for the past several years to make "-tan" versions of electronics. These are cute personifications of game hardware or even computer operating systems. Most recently, Microsoft released the official Windows 8-tans ; however, most of these "-tan" creations are not official. They are fan creations, like "Siri-tan".
Everyone's favorite virtual personal assistant is making her totally unofficial album debut, with enough logo tweaks to (hopefully) avoid the wrath of Apple's attorneys. One of the tracks, "Hello Siri-tan", first hit online this spring. You can hear it here. The six track album even features a rap battle with Android's voice app N2!
The personification of Siri into a cute anime girl isn't unexpected. Siri-tan's personification does vary: sometimes she's a bookish librarian type and other times she's decked out in a necktie and underwear.
So what's with the butt motif here, you may be wondering. In Japanese, "siri" is "shiri", because "si" is "shi" in Japanese. And "shiri" (しり) can mean "butt" (尻) in Japanese. So "Siri" not only evokes Apple's personal assistant in Japan, but asses as well.
世界初、「Siri」の擬人化CD「おしえて しりせんせい」リリース決定 [IT Media]