Gattis' stance looks much more crouched than I remember. He hasn't gone the full Jeff Bagwell yet, but he's spread out and lower to the ground. With the help of Talking Chop's Braves prospect expert CB Wilkins, here are two pictures of Gattis. The one on the left is from 2011 when Gattis was in Rome, and the one of the right is from 2012 when Gattis was in Lynchburg.
You can see that he spread out a little more and got into more of a crouch, though no where near what Bagwell was like. The stance is actually sort of trending towards what Albert Pujols' stance looks like. Take a look at Pujols' stance:
I guess if you're going to model your stance after someone, it might as well be one of the best players in the game. It's not certain that Gattis is directly copying Pujols, but they are both similarly built players with strong legs, and in well-coached organizations they will be taught over time to use those assets.
Now let's all freak out and get overly excited because I compared Gattis to Pujols.