I was informed: Like the previous picture this is actually a chamber that had some cultic purpose. The relief across is the Sungod. On the left is a relief of Shuppiluliuma II (not visible here), and on the right is the Luwian hieroglyphic script belonging to him. It was suggested that the rooms were symbolic entrances to the netherworld.

Note the figure (barely visible) in the back, some god or king, priest ....