Unfortunately I havent had chance to see your film yet due to concentrating on some projects, but i really like this image.
If i looked at it as an image and didnt know it was from the film, I would say that it looks like the dog has a bit of a rough time. The person holding him is somewhat standing in the light but there are creeping shadows around to suggest that the dog isnt in the light most of the time and is in fact in darkness alot. Which could be sadness or sorrow or just a bit of a rough time, but his owner pretends everything is fine, illustrated by the light.
With the hearts on the chain, it suggests his owner cannot show love emotionally, so they have to show it through material goods.