After the Death Gun incident in Gun Gale Online, Lisbeth and Asuna invited Sinon to join Alfheim Online. She created a new avatar and chose the Cait Sith as it has the best eyesight among all the nine races; quite useful, considering how Sinon prefers to attack long range. The Cait Sith has cat ears and a tail, the late of which Kirito pulled as a joke during the expedition of the retrieval of the Holy Sword Excalibur.
Oh wow, that is an amazing looking Sinon! I really love the effects in this photo! It makes her look like she’s actually in the game! Thanks to Hugo for sharing this!
Source: Hugo Greco on Google+