What is wrong in the picture? Correct it to make the bulb glow.

Hint: We know that for any circuit containing a bulb, the bulb will glow only if the circuit is complete. This includes keeping the key closed and also making sure that the electricity can pass freely through all the elements of the circuit. Keeping the above in mind, we can solve the question as discussed below.

Complete step by step solution:
 Let us first look at the circuit and identify its component, from the figure we can identify that the circuit contains a bulb, battery, switch, connecting wires and a rubber piece.
Clearly from observing the diagram given in the question, we can say that the circuit is closed, assuming that there are no loose connections and the battery is alive, that is it can produce electrical energy.
However, since rubber is an insulator, it does not allow the flow of electricity through it. Thus the circuit may look complete, but it is actually incomplete. Hence the bulb does not glow.
Thus to correct the circuit, we must replace the rubber piece with a conductor, like a metal like copper or just using connecting wires, which is also made of copper wires as shown below.


Note: Other possible cases could be the connections are loose which means to say that there is air passing between the connecting wires since air is an insulator of electricity, the bulb will not glow. Another possible reason could be that the bulb is fused or that the battery is dried, or is old in either of which the bulb will not glow.