Mesh for those who don't already know is the newest building technique for Second life. Though mesh is now incorporated in all sims it still requires you to have the appropriate viewer to see the new graphics and can cause some hilarity when your viewer doesn't support it as objects, clothes or avatars can look like a badly textured beach ball or biscuit. In the above example GFC's resident Klingons Kal Aie donned a mesh outfit and we can see how it looks from 2 different viewers.
Which do you prefer the Biscuit look or flamed sworded skeleton?
If your present Second life viewer doesn't support mesh then you can try it out with these popular updates.