Pencil on paper - 50x50
The reason for the square paper? Composition! The more you crop off parts of your subject, the closer it will move towards you.
This one is uncomfortably cropped. Half of his eye falls off the paper. Which allows him to draw attention to his other eye.
With a determined stare, he pulls down one eyelid with his finger, almost suggesting he can see you... or even through you!⠀