Imagine your friend made the following circuit for a curious experiment:
If he connects both the wires to a single terminal of the bulb, the bulb starts glowing as soon as the wires are connected to the cell.
As the two terminals of the cell are connected to a single terminal of the bulb, this condition is similar to the one in which the bulb is not connected to the circuit at all. Hence, the bulb does not glow. The bulb would have glowed if both the terminals of the bulb were connected to the terminals of the cell.