The chocolate ingredients are placed in the pot. The "molinillo" is placed in the pot and then the cover is placed over the handle of the molinillo. With the cover in place, the user holds the molinillo between his two hands and with a rubbing motion froths the liquid. The pot is held from the top and side handle to pour the chocolate into cups.
The pot shown above was produced in the 1940's to 1950's. It is no longer made and not available for sale. Click the "buy link" to view a chocolate pot that is currently available for sale, made in France.
View this link to see more examples of chocolate pots.