In Chapter 1, Alice personifies the snow and the trees and fields it falls on outside the window:
["]I wonder if the snow loves the trees and fields, that it kisses them so gently? And then it covers them up snug, you know, with a white quilt; and perhaps it says ‘Go to sleep, darlings, till the summer comes again.’ And when they wake up in the summer, Kitty, they dress themselves all in green, and dance about—whenever the wind blows—oh, that’s very pretty!” cried Alice, dropping the ball of worsted to clap her hands. “And I do so wish it was true![...]"
Alice thinks of the snow as a loving parent to the trees and fields. She "wonders" if it tucks them in for the winter and speaks lovingly to them. This love from the snow, she imagines, might help the trees and fields wake up joyful, ready to "dress themselves all in green, and dance about." The snow is no longer there when the trees and fields wake up, but they are prepared to dress themselves and dance even without the snow there to love them.
The way Alice idealizes the parental relationship between the snow and the trees and fields suggests a certain longing on her part to have a parental figure help her grow up as happily as she imagines the trees might. The words "wonder" and "wish" indicate that Alice does not actually believe in her personification, but that she yearns to. It is possible that she simply wants the trees and fields to experience the kind of parental love with which she herself is familiar, but there is more evidence to suggest that Alice is a lonely child who spends a lot of time daydreaming about the kinds of parents she wishes she had. In Alice's Adventures in Wonderland, Alice's governess is there mainly to scold her for her daydreaming. Even this authority figure is absent in Through the Looking-Glass, in which Alice falls asleep surrounded only by the cats. In fact, Dinah seems to be a more present mother than any parental figure in Alice's own life. Alice's wish for the snow to love the trees and fields so that they can come to life in the summer seems to stand in for a wish that someone will help her turn into an adult who can dress herself and dance with joy.
Carroll may be responding to his own isolation from Alice Liddell, the little girl who most likely inspired the character of Alice. The real Alice's mother had cut off contact between Carroll and Alice since the previous book had come out, and Carroll may have been upset that he could not be such a present adult in the little girl's life. Carroll himself had endured neglect in childhood, so he may have been projecting his own experiences on Alice Liddell, as well.
In Chapter 6, Humpty Dumpty claims to be very good with words. As he describes the way he manages them, he personifies them. This personification draws out the situational irony of his claim that he is a wordsmith:
Alice was too much puzzled to say anything; so after a minute Humpty Dumpty began again. “They’ve a temper, some of them—particularly verbs: they’re the proudest—adjectives you can do anything with, but not verbs—however, I can manage the whole lot of them! Impenetrability! That’s what I say!”
Humpty Dumpty claims that verbs, especially, have a "temper" and are the "proudest" of all parts of speech. Adjectives, by contrast, are more docile. Words don't really possess human traits, but Humpty Dumpty imagines that they do because he feels that he can wrestle with them, interpreting any poem and making any meaning he wants to out of words.
The idea that Humpty Dumpty can "manage" words and make meaning out of them is ironic because he himself is the creation of words. Humpty Dumpty comes from a riddle, or word game, to which the answer is "an egg." The fact that he is posturing about his way with words comes through at the end of the passage above: instead of continuing to explain to Alice how he can make words mean what he wants them to mean, he simply cuts the conversation short by shouting, "Impenetrability! That's what I say!" When it gets too difficult to make words make sense, he can simply call them "impenetrable" and move on.
Carroll is making light fun of literary criticism that tries too seriously to wrestle meaning out of everything. Some literary critics stop analyzing as soon as words stop making sense, claiming "impenetrability." Carroll, as a pioneer of "nonsense literature," is always playing with the idea of "impenetrability." His work challenges the idea that "logical" words and ideas always make sense when we look at them closely. It also challenges the idea that we can't mine any meaning out of things that look like they make no sense at all. Humpty Dumpty is a silly caricature of literary critics who refuse to approach their work lightheartedly enough or to let words take them into playful new terrain.
