Basically the idea is that if you say “show me that picture of me standing in a line with a bunch of losers waiting to buy you” Siri will do it. Users would be able to tag the photos as they take them, with one example quoting a user saying "This is a selfie of me and my inflatable woman” with other photos in the same geographic location tagged accordingly.
According to the application, the tech would also recognise faces, buildings and landscapes to apply tags to photos in the iOS Camera Roll.
Naturally, users would then be able to call up those photos at will by using Siri to say "show pictures of me at the beach" although Siri will be hardpressed to show any outdoor snaps. The application itself was published in March 2013, so if Apple plans to follow through on the feature, it's somewhat surprising the functionality wasn't built into iOS 7 after all it has nothing else which is new to put there.