I've never really seen a howdah design in the reliefs. All I have seen is some sort of cover, roof for the person in the back. I dont know if this is a simplification of a howdah design. No good references(historically accurate painting, drawing, etc) of a howdah design from then. :/ If you guys insisted on a howdah design this is the closest good reference I have found. Before the Islamic invasion of India.