(My first critique so sorry if i'm not going through much detail >w>")
Firstly i'd like to say that this is amazing, the shading is good a little too soft on Sally's hair and clothing on the left face, isn't easy to see shading. I can see that you have tried adding detail in the hair (on the left face with purple lighting), but try adding highlights in the hair to give Sally's hair more realism ^^
Other than that you just gotta love those eyes. They are so detailed, i can tell that you took your time on the eyes with this piece of digital art! ^^ And with the tears too of course, they're better what i can do *isjealous* ;;w;;
With the Vision of this digital art, it is very clear to me and looking at other comments everybody else as well. I could tell without reading the description that Sally was possibly possessed on the left whilst she was upset on the right, Sally looks like two completley different people on both sides which also justifies the different emotions that you the art envisioned and us the viewers can also see! ^^
Overall i think this is a lovely piece of digital art and shows very clearly within the art itself Sally's emotions! ^^ I need to watch you hahah XD
Oh and about the shading i do like how you shaded Sally it's just that it wasn't suited for this specific piece of digital art incase i confused you ^^"