JMich: I think it's not Dwarves, but another race. But since I cheated by searching the image, I'm not posting an answer.
AFnord: Well, there is a mod for Dwarf Fortress called
Goblin Fortress, which allows you to play those rascals.
But when you see a lot of g in a dwarf fortress image, it usually means goblin siege.
Correct race, wrong game I'd say. And I did manage to find the image posted as well. If noone guesses it in the next day or so (or if Lifthrasil allows a google searched answer) I will post the answer.