The correct answer to this open question is the following.
Although there is no more context or reference, we can say the following.
The activities that should take place during the performing stage would be the following.
During the performance stage, the leader and the members of its team are ready to start taking action. After passing the previous stages of the forming stage, the storming stage, the norming stage, it is time, the leader knows that it is the moment to do what was planned. So this performing stage determinant because actions are going to be evaluated to know the effectiveness of the leader. So the leader knows that he/she has to be congruent with what it says and what it does, and deliver the proper results for the benefit of the team.