According to the documentation from K2, View Participate (Process Right) allows a participant, i.e. the user defined as the destination user for one of the process activities, to view the details of the process instance. The user will only be able to access process reports and the activity instance once it has reached the activity for which they are a destination user.
i have a destination user called jdoe and when a task is assigned to him, he is not able to view the view flow.
His process right for this process is Start and View Participate