In the Transformation scene they sing "Everything will become clear to you when you see things through another's eyes." in Inuit. Well, when Kenai has his flashbacks to when he and Koda's mother faced off... he's remembering them at least partly in bear. He's hearing them from a bear's point of view, and everything finally makes sense now that he knows why Koda's mother did all of that.
When Koda's mother speaks in Kenai's flashback, he finally understands her - she's even talking in human when she stands and calls out for Koda.
When Kenai is tracking her earlier in the movie, a moose briefly appears looking more realistic than Rutt and Tuke. Once he's transformed into a bear his perception literally changes, giving all the animals more expressive faces and movements.
Meta in a sense with regards to Kenai's totem. Bear + love/affection = Care Bears. Is it such a wonder he's disappointed? He should have been utterly mortified!
At the Salmon Run, when they're playing "Pass The Salmon", all of the bears are telling stories of friendship and love - from the two bears now mating, to the big bear who's allowed a family of chipmunks to move in with him because he pushed down their tree. Totem of Love, everybody!
When Tanana jokes about totems, everybody laughs, and she does too, but if you rewind her age appearance you can actually see that in her youth she may well have been quite attractive.
Tanana: When each of us comes of age, the Great Spirits reveal to us a totem that helps guide us through our lives. Some of us use courage to guide us, others patience. And some of us, beauty...
At one point in the movie, Kenai and Koda come throught the wall adorned by cave paintings, which according to the novelization is located in an abandoned village. What happened to the people who lived there? The most likely theory is that when the resources ran out, the tribe living in this place went looking for a new place to live, but the second, darker theory may be that something killed the people living in this village (some sort of plague or attack of predators).
Did Denahi really mistake Kenai for the bear who "killed" him and actually try to avenge his death by relentlessly trying to kill him and Koda until Sitka finally stops by immediately changing Kenai back at the last moment... ...or did Sitka manipulated Denahi into doing so just to teach Kenai a lesson about what it'd be like to be the bear who gets hunted all the time? (Kenai's first transformation is portrayed in a way so that Denahi never sees him transform but the viewers do, Sitka leading Denahi to the same mountain Kenai is traveling to initiate the final confrontation, and Sitka not changing Kenai back until after Koda starts defending Kenai from Denahi's attack).
No, Sitka knew that Kenai, having had experience as a hunter, would be able to evade and escape Denahi. For a brief moment, Denahi almost considered giving up, until Sitka's spirit guided him. It's more likely Sitka wanted Kenai to prove that he had learned his lesson and for Denahi to learn that his brother is actually alive.
How long has Denahi been chasing Kenai and Koda for?
A bear's lifespan is around 25 - 35 years, meaning that when we start out the movie by seeing Denahi as an old man, Kenai and Koda (as well as Nita) are all long dead.
Given Denahi refers to Kenai and Koda in the past tense, this is probably confirmed.
However, this can also become Fridge Heartwarming if one considers the fact that Koda's mother was able to revisit him as a spirit, so it's possible same applies to them.
