The film's Logo Joke is of the Universal/Legendary logos being covered in ice and snowfall. This fits the story's winter/Christmas setting and is also the first part of Krampus's arrival. The Engels' neighborhood was surrounded by ice and snowfall, imprisoning the family to be picked off by him and his minions.
When Tom and Howard went searching for Beth and explored her boyfriend's house, notice something. The Krampus's gingerbread man is seen stabbed on the fridge, and the fireplace is opened like how Krampus came down the chimney later. This means that a stoner teen (and possibly his family) held off Krampus's minions long enough that Krampus had to personally get involved.
At first, this troper found that the split-jaw on the Jack-in-the-Box Jester was somewhat pointless and appeared to just be there for the sake of being scary. However, it makes sense when you see it swallow Jordan whole. The split-jaw allows it to unhinge its jaw like a snake to swallow larger prey!
Krampus' controversial appearance at first seems like a case of Special Effects Failure, because it doesn't move. Then you realize, it's a mask.
In the closeups, you can see Krampus's real eyes behind the eyehole of the mask, and in the official tie-in statue, you can see his real mouth behind the mask mouth.
The scene early on about how Santa's present-day image was created by Coca-Cola takes new relevance when you consider how heavily it's implied that Santa is Krampus. The inclusion of elves, a workshop, and a sleigh only make this more likely.
The attempted Take Me Instead is what saved everyone. By displaying the true Christmas spirit, that of giving even at cost of ones self, the scales of how bad the family had been vs their coming together now finally tipped back in their favor forcing Krampus to back off. The drop into hell was his attempt to spook Max into retracting his offer.
"You better watch out/You better not cry..." How fitting that the film ends on a mass Jump Scare.
At one point, soon after Howie Jr. is taken, you see that one of the snowmen looks an awful lot like him. We know some of their neighbors went to Hawaii and Florida for Christmas, but Beth's boyfriend was still home. Tom even wonders where all the people and cars are. I don't know about the cars, but I'd bet their neighbors are closer than he thinks. They ARE the snowmen.
The jack-in-the-box is usually a fairly slow-moving beast, so how would it have managed to ambush the kids in the attic? It swallows one and knocks the other unconscious, so the attack must have been rapid. Considering what kind of a toy it is brought up a likely answer: it popped out of its box as they walked by, slamming into them before they could react.
Although given that it used Beth's voice, it would appear once he swallows someone he can use their voice. There is some very serious fridge horror if he can fit back into his box when he's got someone inside of him. But he could use both ends of himself, as in have eaten the one and used his box to strike the other unconscious with a blow to the head.
Actually, according to the storyboards on the DVD and Blu-ray release, it was actually Perchta the cherub who was mimicking Beth's voice since she was originally going to cruelly taunt Sarah while attacking her by calling out for help in Beth's voice. Though that doesn't diminish Der Klown's scariness one bit.
It does make sense to allow one of the other toys to do the voice, but without knowledge of those boards, it also isn't hard to see how one would assume eating could equal stolen voice.
Krampus's game here appears to be capture, so Der Klown is merely holding them inside of himself. Did he have to vomit anyone back up?
