The venue of the auction was the founding museum and gallery, one of the multiple properties owned jointly by the founding families and managed by a committee selected by the founding council.
All the families contributed famous antiques, art and various crafts to be placed in the museum all year round, those things were exchanged once a year, usually at the beginning. If a family wished to retrieve whatever they had placed in the museum, they had to bring a replacement of the same value.
The preference for the art and various antiques was simple; old, rare, with historical meaning and worth a lot of money. All this information was shared by Aunt Maureen. She was doing most of the explaining to Phoebe who didn't have the heart to tell her that she was familiar with the information.