They are both very beautiful girls and both photograph very well. What I'm seeing (only my opinion) is that Lacie is more of the closeup type while Shelby does quite well full or even upper torso body shots.
Re the two photos you show, I like the pose in the first one best but I like the second photo better. For some reason, and it is a real small nit-picky thing, the blue fingernail polish really clashes with the red dress in the first photo and is one of the first things I'm drawn to. Yep, I'm strange.....