These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Which plays a part in Nick's later action in the scene where Clyde gets the gift he always wanted from Santa.
Also the entire Christmas morning sequence, with a beautiful rendition of Silent Night playing and Nick telling Fred he's the best big brother anyone could ever ask for.
Strawman Has a Point: Fred's comments to the bratty girl while he's repossessing her Christmas gift, a big-screen plasma TV. He says he's doing her a favor because if not for him, she would be addicted to television and overweight.
The Woobie: Fred, YMMV on if he's bordering on Jerkass Woobie. Kinda hard to dislike him when you realise that for most of his life he's had to deal with his parents constantly telling him to be more like his brother, even though he was already kindhearted - he gets told off for getting upset that his brother just gave away the present he'd clearly put a lot of work and thought into, and without so much as a thought towards the effort he put into it.
Nick as well, who is burdened and stressed by everything throughout the entire movie, and he's just so broken by it all near the end before the happy ending transpires.