Art History--test your knowledge

Now that school is finally out I have a little time and hope to update with some of my art form this spring sometime soon. In the meantime, here's another art challenge!

But first, the answer to the last one. The image was "The Presentation in the Temple" by Ambrogio Lorenzetti from 1342. Originally part of an altarpiece (many were cut apart and sold in pieces through the centuries), this painting is considered one of the first accurate and realistic portrayals of an interior space since Roman times. Quite beautiful. Ambrogio painted the famous frescoes of the Allegory of Good and Bad Government in the Palazzo Pubblico in Siena (the town of which was the artistic rival of Florence for a time). His brother Pietro was also an artist who painted some of the frescoes in the lower section of San Francesco in Assisi. Both brothers died during the plague of 1348.

Now, on to the new. This time I am presenting a famous double portrait from the Northern Renaissance. The men pictured were friends, from France. One was sent as an ambassador to London and his friend, the bishop in the picture, was visiting London. The items on the table each represent different aspects of the two men's lives. I'd love to hear your thoughts on what the items mean, but what I really want to know is what is that strange object in the lower foreground of the painting and why is it there? Happy hunting.