This is an example of one of the "Hanging Windows" that were painted on the central panel of the walls of the box.
The artwork on the upper part of the walls created an illusion of real "hanging pictures" of windows, painted on wooden panels, with their shutters open wide to an imaginary view. The illusion was enhanced by the painted strings and nails on which the pictures supposedly "hung," and latches for the shutters.
Pictures like these were rare in the Roman world and are unique in Judea. The views included landscapes, buildings, animals, and human figures. The quality of the work and its Egyptian scenery suggest that the artist and his studio were from Alexandria, employing an artistic style reminiscent of sacred landscapes from the time of Augustus. The themes of the paintings, like a crocodile and a palm tree, which also appear on Augustus's victory coins, allude to the Roman conquest of Egypt. (from a sign at the Herodium)