As Andy Goldworthy says in his documentary River and Tides, "Why talk about sculpture when you can photograph it". Meaning I suppose that if sculpture is worth talking about then it probably doesn't need talked about, just look upon it and it will say all it needs to say.
That being said, discussion could arise from whether it speaks differently to the individual.
{Lamp installation and photographs by Rune Guneiussen}
{Melting Men installation by Nele Azevedo calls attention to global warming, Image via: Inhabitat}