Like every other iPhone VNC app, except totally in reverse: It's a server.
Far from a novelty, the ability to log into your iPhone with a desktop VNC client is actually really useful. Imagine typing on your iPhone with a keyboard; now install Veency, and actually type on your iPhone with a keyboard.
From the App Developers: If your device has ever been just out of reach, this package is for you: you'll never need to touch your iPhone or your iPod Touch again! Instead, sit back and enjoy the comfort of remotely logging into your phone via VNC. You can view the screen, touch controls, and even push the lock and menu buttons all from the comfort of your desk- or laptop.