Gonna give this a shot:

So, the first thing I notice is the shading. For the most part the light source is consistent, coming from the right of the image. But then there's the shading on top of 18's left arm that looks like the light source is coming from below. Additionally, 18's shirt and Laine's hair go from dark gray in the light to brown in the dark, which doesn't look right to me. Otherwise, the figures are well drawn, albeit 18's pose is a tad off, but that can be justified by the situation explained in the deecription. The lineless approach to the background is also a nice touch.