Does your client require the figure to be in the pic? Or so prominent?
Does the pic need to be realistic?

I was just thinking of many old Sci-Fi covers from 50's-70's.  Many had pictures that were not true to reality.

You could use Ringworld (or Halo) as an example as seen behind a character.  These are completely unreal.  The atmosphere is very thick  and would block out the view of the ring.
But reality  is not important so the ring and it's day night squares can be seen even for several million miles away.
If you spread the Ringworld in the background across the whole pic, it would not be clear that it is inside a hollow planet. 

From the POV you have now I don't think it is possible to get the point across that it is inside a hollow planet.  A view with the figure looking out over a scene that is fisheye distorted might work.  Take a look at the original cover for Rendesvous with Rama for an idea of inside a cylinder.  Also look at Star Trek II in the Genesis cave.    

Sorry for the ramble, late Friday night and tired.

Here's a funky Sci-fi cover site.  http://www.krazydad.com/visco/