Ok, let's break down this new pic. I'll give some things I noticed and you put your opinions down below :)
-it seems Clem and Luke are still near the cabin area in the forest, this might be when they're heading to the mountains
-Where is the rest of the group? Are Clem and Luke on a mission by themselves?
-There is a broken down bridge in the background, I wonder if Luke and Clem are coming from it or are heading towards it?
-The bridge has a rail, possibly for a train or cart. At the end if the bridge there seems to be some sort of mine art or a similar cargo carrying vehicle
-Clem's weapon if choice is still her trusty hammer
-Clem is about to smash a Waker's brains in, but Luke looks startled to see this. Why? Does he knows this walker? Does he not want he to make noise?
Post why you think Luke us running towards her and anything else you notice :D