Adaptation Displacement: Not as common as with other Disney films. Many people don't distinguish between "Alice in Wonderland" and "Through the Looking Glass" (or simply don't know), and the film's mingling of the two exacerbates this.
The animals in the Tulgey Wood. Especially all the strange looking birds. Who's a cute widdle living birdcage?
The Glasses Birds especially. They're pretty much Adorkable personified (as birds).
The Cheshire Cat, although he's more "Creepy Cute". Alice's reaction when he first shows up implies that she thinks this too.
Vindicated by History: The film opened to a lukewarm box office and mostly hostile reviews in 1951. Walt himself voiced Creator Backlash against the film and famously declared that it had failed because "Alice lacked heart" (it's somewhat unclear whether by "Alice" he meant the film or the character). In the decades since, it has become better regarded by both critics and general audiences and is now thought as something of a minor classic.
What an Idiot: While the Bird in the Tree mistaking Alice for a serpent made some sense in the book, as only Alice's neck grew longer and she could only see Alice's head and neck, this film makes her look like even more of an idiot.