The Kirov, and most of the other ships on the Periphery, are made of really crappy materials- lots of dirt in the plasteel, and high oxidation, so that a bit of nebula makes it look like it's been left in the rain for two years. This thing couldn't stand much gravity for too long- maybe a short landing and takeoff, but it'd be liable to snap in half if you assembled it on the ground.
The front part's just a shiny chrome metal, the sort of thing really fancy battlecruisers are made of. It just is. It's not actually that reflective, it just has a bright light right in front of it.
And the high-specular back bits and turrets are all-procedural, which just highlights more. I dunno.
