My thirst thought when looking at this was "dark." But also different. In a good way.
Most of the other submissions I've seen so far that go with darker themes make it more like Santa is threatening them to get their work done (I did the same thing, admittedly). But this is dark in a much different way. It's original and the message is powerful. I don't think you missed the point at all, I think you hit the nail right on the head, and you did it by coming up with something entirely different and new.
The art style alone is a very interesting one. It kinda reminds me of an illustration from a Roald Dahl book. It's not something you see very often, but it does a really good job at conveying that this isn't a lighthearted, happy, or funny illustration in the slightest and it kinda does give us a sort of feeling that this was illustrated for a kid. Smaller details like the wallpaper being torn, the bottles littered around, the idea that this man has fallen asleep on his kid while watching TV, the santa hat.... Every little detail does a great job at story telling. It tells us everything we need to know about this little girl's life. We know how sad and hopeless she feels and that their living situation is awful, we know that they probably can't afford a Christmas because the house looks like crap and the dad probably spends his money on beer. We know that all she has to look forward to is Santa coming over on Christmas Eve to leave her something that will make her day, heck, it'll probably make her entire year. That hat is dirty, showing she's had it for a while and it's probably one of the only things she has to hold onto, so she probably takes it with her everywhere. Her face is covered, meaning that she's probably crying while doing her best to hide it. It's really.... Powerful. It's moving.
Though it's really dark and sad, this could definitely be something that elves would look up at every so often and think, "Shoot, that's right. This is why I do my job. This is why I'm trying so hard. I need to keep moving for kids like her. I need to work my bum off for her." It's very... Well thought out. I really like it.
Overall, I don't care what anyone else might think of this, I think it's amazing. I think you did a great job of sending your intended message and I'm a little sad to see that others have overlooked this art piece. Great job, mate. You really moved me with this one. Please forgive the super long review. I hope it was helpful.