The cup is the only object from the painting that we have in our collections at Norwich. It was given to us by the same Norfolk family, the Buxtons, who gave us the picture, in the late 1930s or early 1940s. No written records exist, but it seems likely this same family bought both picture and cup in the early 18th century, when the Pastons' treasures were sold off.
If you look closely and compare the real cup with how it looks in the painting, you will see that the shells do not quite match. The original shell must have broken, and been replaced with another. According to our natural history curator, both shells are rare specimens. They would have been highly prized in the 17th century.
The other thing to notice is that the intricate enamelled flowers on the cup's mount are rendered more simply in the painting than they appear in real life. The artist has given himself a little 'artistic licence'!