This was already a very emotional scene in the book, in the movie as well. Snape still loved Lily, and it was so sweet!! With his whole intentions in the story made him one of the best characters!
You captured the scene, quite well. Every detail is so precise its amazing!! Just looking at the picture melts my heart.
I noticed apart from Snape's cloak the picture if very light. If you wanted to capture the scene more, perhaps darker layers. (Though its fine the way it is, but if you're looking for more emotion that's a good way to do it).