Price discrimination is manifested in the above scenario because the charge of one and the same flight is different on different passengers.
Flight rates of the same flight should be the same. It should not be dependent on who the passenger is.
In the above example, it would seem as though the flight rate is dependent on how the airline employee perceive the passenger. If the employee see that the passenger is affluent, then the flight charge is high. If not, then the flight charge is the usual flight rate.