What is abbot suger holding in the image in the image below?

In the image attached, Abbot Suger is holding a model of the Jesse Tree Window, which he personally donated to Saint-Denis.

About the Image:

Abbot Suger appears as a kneeling monk at the feet of Mary in the Annunciation panel of the Nativity window at the east end of St. Denis.  The head and hands of the monk are 12th-century glass and most of the rest is the 19th century.