The tricks to Poser reflections:

1.)  Make sure the Raytracing is enabled in the Render Settings.

2.)  Make sure your Material is Reflective.  Post us a screenshot of your Advanced Material Room!

3.) And understanding a Poser scene.  The ends of a Poser scene are empty; null of Objectivity.  Without Objectivity there is nothing to react through with your Reflective Material!  So you need to insure the alien, and everything around him, is angled properly.  If all you want in the reflection is your alien, then you just need to tweak a little; but if you want a background from beinf he alien, in the relfection with him, then you need to add that.  The easiest way to do this is with a Sky Dome.  Or you could you any Envirmonment you want, as long at is totally encompassing.  I like Sky Domes because the mapping technology, for the inside of a sphere is very advanced; you do'nt even know you're looking into sphere:

(Care of patorak)