If the center of mass of a top is not located directly above the support point, gravity exerts a torque on the system, and the position of the rotation axis changes. This effect is called precession and is a direct result of the vector nature of angular momentum. We don't want to treat this mathematically here, but on the other hand you can demonstrate this effect quite nicely. The two videos show the same top (big black disc) which is rotating in the same manner in both cases, which means that they have the same angular momentum. The difference between the two videos lies is the position of the small counterweight (small black disk). With this counterweight one can move the center of mass to either side of the place where the rod is supported. The gravitational force acts as an external torque for which you can change the sign. The results are clockwise and counterclockwise precessions.
Please note: This material will not be tested. It is included just for the fun of it.