Reader Sara sent this information:
The Palazzo Zuccari was designed and built by Federico Zuccari, who also lived here and used it as a studio for his painting. The palace was erected in the 16th Century and has undergone numerous restorations over the years. During the 17th Century it was home to the Toscanelli family and in the 18th Century home to Maria Casimira of Poland. The door and windows are quite striking and were designed to resemble the face of a monster with the door as an open mouth and above it a large nose, two eyes and ears.
It looks like he's taking a big bite out of the tree!
The windows on either side of the door are slightly different. I love the round window!