New hair!!! Her outfit looks mostly the same but this new haircut gives her an older look signaling how much she has been changed by the events in book three. Personally I love it! I much prefer this to the ponytail she has been sporting for a while. I also love this art as it shows that Korra is looking very determined to overcome what happened in book three.
What do you guys think?
Source: Bryan Konietzko's Tumblr