well, I set all ambient settings to zero, added a envrionsphere, loaded a texture which would be somewhat appropriate ( an interior view) and swapped the single color of the ibl lite to an hdri matched to the sphere texture, added a back wall (which didn't exist) to close the scene from behind and added a while paint texture to it. Then I changed the  infinite light to a point for more drama since its placement, implied to me, a glass wall of some kind on the balcony reached by the stairs. I then turned on shadows for the fill lights, in reality all lights create some kind of shadows even for master photographers with lots of reflectors and assistants of which the shadows were assigned as raytraced. Last but not least all the textures were set to crisp. Oh and I changed to metal shader to a basic chrome instead of the sphere mapped in the original.  Here's what I got: