Twin trickery

During the famous ‘lady in the red dress’ scene where Neo is training in a small version of The Matrix known as The Construct, several extras in the background are twins, to show that Neo needs to pay attention to his surroundings, as not every is how it appears to be.

It also cleverly demonstrated how The Construct was created, with Mouse (Matt Doran) copying and pasting in several templates of characters multiple times, just to fill out the world.