The reflections on the window, the way the light is falling on the face of the watchful dog, its pose--the scene has so much potential of being converted into a work of art. However, in my opinion this picture is a rather ordinary snapshot. I know this picture of your dog has a high emotional value for you, but keep in mind there are thousands of dog pictures out there. Here are some tips what you could improve to increase the impact and to make it stand out more:

The dog is placed right in the center of the shot, which makes the overall picture look static and rather boring. Placing your main subject off-center makes the picture more dynamic and eye-pleasing.

The chair in the foreground draws away from the dog. Maybe you could zoom in more and focus on the dog's face/profile, thus removing all distractions and catching the dog's expression better. By zooming in you can also reduce the depth of field and blur the backround a little more, which would add some depth.

Moreover, try to take animal pictures from the eye level of the animal. This adds more intimacy and expression.

If you want to play with light and shadows maybe you should consider converting the picture to black and white.

Scenes like these are spontaneous and hard to catch because you have to be quick at pressing the shutter but keep shooting--practice makes perfect