A lovely interpretation of a sad but beautiful moment. Luckily, I know how the story ends. :)
The sorrow on their faces is palpable, and the “touching” hands emphasize the hopelessness in a quiet, understated manner. A nice introduction to the actual scene.
Snape’s portrait looks gorgeous in the high-res version. There’s a wonderful sense of vividness and depth, of life and real emotions, that the canvas-like surface cannot hide. In fact, I think the texture enhances the “alive” feel of the painting.
The bookcase in the background invites thorough perusing, and the stool is elegant. The best part is Severus, though. I like the way he is sitting, so casually, left arm resting on his knee, while the right one reaches forward. His clothes and hair look great against the pale face with its subtle lines.