Style of Animation

Seeing that the woman is deceased, I thought that having her perfectly animated in terms of making the animation really crisp and clear, would make her look too real and alive. I reckon a style of animation would help show that she is deceased and a memory from the past so to speak.
In movies, ghosts tend to have an outer glow, are slightly transparent (Casper) or have slow or wispy movements (like leaving the onion skinning on) etc. Using this type of approach to animate and better show the state of the woman I feel would work really well. Also how the man doesn't have a clear image of how she looks anymore, this would further help this method.