Figure I shows a pair of charged aluminium leaves that are attached to a metal strip. The leaves are shown as moving away from each other because they are charged by the same kind of charge. When Hari touches the metal strip, the leaves move towards each other and become relaxed, as shown in figure II.
The leaves move towards each other because :
they loose their charges
When brought into contact, the charge on one body can be transferred to another body. This is called charge transfer by conduction. When Hari touches the metal strip, the charges on the aluminium leaves get transferred to his hand, through the strip. At the same time, the hand loses the charges to the earth, through the body. This process continues until all the charges from the leaves get transferred to the earth. Hence, the aluminium leaves become uncharged, move towards each other, and become relaxed.