Despite the name, the Grinch in this film is nowhere near as heartless, antisocial or "evil" at the beginning of the film as he is in previous adaptions— while he's certainly pretty grouchy and cynical, we do see some shades of good in him, particularly in how he treats his dog, Max.
The Grinch is shown to be significantly kinder to Max than the Chuck Jones or the Ron Howard version, generally by treating him more like a typical dog owner would. He plays with him, apologizes when he upsets him, and freaks out whenever it looks like he might be hurt. Also, though Max is still the Grinch's Morality Pet, he's genuinely loving/loyal to his owner and willingly goes along with his plans — if this is something the Grinch needs, then Max is completely on board.
One sweet moment the Grinch has with Max is when Grinch tries denying Max's plea to sleep in bed with him before ultimately relenting—granted, not without humorous complications when Fred gets involved. The Grinch grumps about it for a few seconds...then falls asleep with an arm around Max and a smile on his face.
At the beginning of the movie, the Grinch is prepared to go hungry rather than brave Whoville in the Christmas season for groceries. Then Max nudges his own empty food bowl, and the Grinch begrudgingly agrees to go out.
At least one viewer has pointed out that Max quite literally serves as the Grinch's emotional support/service dog, helping him get out of bed in the morning and with basic self-care tasks like feeding himself and showering.
The movie is just filled with little moments of affection between the two that’s absent from the Chuck Jones and Ron Howard versions until the end. Max puts his head on the Grinch’s knee, who scratches his ear in response. The Grinch showing concern for Max’s well-being when Max digs himself into the snow trying to pull the sleigh. Heck, the sleigh originally had a doggy-sized sidecar when Fred was still part of the team. The Grinch even assures Max that it’s okay…when the Grinch is the one dangly off the edge of Mount Crumpit with the sleigh! There's a reason why some tie-in material calls Max the Grinch's best friend, after all.
The very last thing we see the Grinch do before the camera pulls back so much that the door obscures him? Snuggling Max.
Though it's far from being mutual (at least first), but the Grinch's presence is pretty well-received in Whoville. The Whos are just as friendly and polite to the Grinch as they are to each other and don't seem to care that he's a seemingly naked weirdo covered in green fur. A Who named Bricklebaum that lives at the base of Mt. Crumpit is particularly gregarious with his "neighbor."
Heck, Bricklebaum genuinely sees the Grinch as a friend, and even proudly whispers that he's his best friend to the Who beside him during the Grinch's toast.
Noteworthy is that for all their noise as well as his distaste for Christmas the Grinch makes an effort to just stay out of Whoville and let them have their fun far, far away from him. Frankly the worst you could say about him before the Christmas heist is that he turns into a petty jerk on the holidays. It's only when repeatedly annoyed, harassed in town by aggressive carolers, and sent into a trauma flashback that he finally snaps and decides to be more proactive with his hatred of Christmas.
Unlike most kids her age, Cindy-Lou can see that her mom's exhausted from having to raise three kids as a single parent along with having to work full-time. Cindy-Lou helps out around the house without a single complaint and wants to ask Santa Claus to give her mom the extra help she can't give.
The Grinch lets Fred go free without a fuss after seeing he has a mate and child.
In previous versions the Grinch recruits Max as his reindeer because reindeer are scarce in that area. But here, he only recruits him because he needs a last-minute replacement after he let Fred return to his family. He even presents the offer as a touching speech, thanking him for being such a good dog, something that Max can be proud to do!
Grinch: Max... you know what you are? You... are a sturdy little fella. And loyal. Very loyal. In fact, I think you're the best dog a Grinch could hope for! And that is why, I'm promoting you. Max, you will guide my sleigh tonight!
After discovering all the Whos' decorations and presents are gone, Cindy-Lou initially thinks that "Santa" took everything because he was mad at her for trapping him and it's her fault Christmas was stolen. Her mom explains to her that just because all the stuff is gone, it doesn't mean Christmas was stolen. As long as she has her, Christmas is still here.
The ending of the film is definitely this. The Grinch is welcomed into the party, and, fulfilling Cindy Lou's wish, helps her mother carry some heavy plates to the table. Even better is that Cindy's mother asks the Grinch if he'd like to carve the roast beast (like in the book). He accepts, but not before giving a little toast, during which he admits that he never disliked Christmas itself—he just didn't like being so lonely.
He further grants Cindy Lou's wish (as per the credits) by making her mom gadgets that simplify her life.
The Grinch giving Max a chew toy for Christmas. It's more poignant due to being after the gift return, which in prior versions was the happy climax, but here, contained an awkward apology followed by the Grinch making a sad and quiet walk home, a shockingly realistic response in a Seuss story. The ending too is surprisingly down to Earth, with Grinch being horrifically shy among all the Whos at a home Christmas party, instead of a grand feast of the town like in prior versions.
The Grinch listening to Whoville singing and his heart growing three sizes. Unlike both past incarnations, it's not played literally or for comedy — he just puts a hand to his chest in joyful, breathless wonder.
Welcome home, welcome home, welcome home...
The Dog Days of Winter short, which sees Max braving a blizzard, falling icicles, and a dog-hating shopkeeper purely to bring a flu-ridden Grinch his favorite tea. He does, and the Grinch invites him up to curl up beside him in bed, where he gives him a deeply affectionate scratch.
Max has a framed picture of him and the Grinch together beside his bed.
Max's response to the Grinch coming back from the Whoville tree lighting ceremony in the throes of a PTSD-driven breakdown. He closes the door when the Grinch fails to do so himself, makes him a cup of tea, and silently sits listening as the Grinch talks half to himself and half to Max. The next morning, he's obviously still very concerned as he brings him up his coffee. Made all the more heartwarming if you're operating under the theory that he's the Grinch's service dog.
