Alice, who has been half-asleep and talking to herself, notices that her ball of yarn has come unraveled. She blames the mischief on Kitty, who is not the middle of being cleaned by Dinah. While she scolds Kitty, she imagines that Kitty responds defiantly to all of her accusations.
Alice then becomes distracted by the winter weather, commenting on how the boys were gathering wood for the bonfire but that it soon became too cold for the activity. She muses about the changing seasons, speculating that during the winter, the trees and fields must sleep beneath the blanket of snow, but that in spring and summer, they turn green and dance. The narrator remarks meanwhile that Alice is prone to flights of fancy which often begin with her saying "let's pretend."
Alice, who has been trying to get Kitty to imitate the Red Queen chess piece, turns her attention to the looking glass, in which she imagines that there is another home, very much like her own, but in which some things are reversed. She wishes longingly for the glass to dissolve so that she can step into that other world. Suddenly, the glass becomes misty, and Alice enters the alternate universe that is a reflection of her own world.
Inside, she notices that there is a fire like the one in her hearth. She notices that the clock has the face of an old man which smiles at her. She also sees that the room is not kept as tidy as the one she left, for there are chess pieces all over the floor. When she gets closer to them, she realizes that they are talking and moving.
The White Queen seems to have lost her daugher, Lily, so Alice decides to reunite them by lifting up the Queen and setting her back on the table. The Queen seems to think that she has been relocated by a volcano, as they are near the fire, so Alice concludes that she cannot be seen or heard in this world. She does the same for the King, and also dusts him off, all of which makes him extremely frightened.
She notices a book and tries to read, but at first she does not understand the language. Then she realizes that the text must be reversed since she is in the looking-glass world, so she holds the book up to the glass. The text is revealed to be the poem Jabberwocky, the language of which she still does not understand. Alice, feeling like she will not have time to see everything if she lingers, floats downstairs and out the door to explore the garden.
Lewis Carroll was known for his love of contrast, so it makes sense that this book opens with a scene indoors in the middle of winter. Alice in Wonderland, contrarily, opened on a sunny May afternoon. The date is also significant, for when Alice is talking to Kitty, she implies that there is going to be a holiday the following day. She is in fact referring to Guy Fawkes Day, November 5th, the night before which was traditionally celebrated with a bonfire at Christ Church, where Carroll studied, lived, and wrote.
The kitten Snowdrop is an example of Carroll including elements from his own life in his literature. He was good friends with a man named George Macdonald, whose daughter Mary had a kitten named Snowdrop. It is actually this family that played a large role in encouraging Carroll to publish Alice in Wonderland, so perhaps the mention of the kitten Snowdrop is a subtle thanks to them.
In this chapter, the reader is introduced to the theme of inversion, which is pervasive throughout the book. Carroll was in fact obsessed with this notion in real life. He wrote some of his letters in mirror writing, and some he wrote starting with the last word and ending with the first. He also drew pictures that turned into other pictures when they were turned upside down.
It is unclear why he nurtured this obsession. One explanation, judged to be inadequate, is that he was left-handed but was forced to use his right, so the inversion techniques were a part of some grand revenge for this travesty. Carroll did do a great deal of work in mathematics and logic, and it is perhaps this passion that encouraged him to explore logical contradiction.
The inclusion of the poem "Jabberwocky" in the book is anything but random. The poem is universally considered to be the greatest nonsense poem in the English language, and it was incredibly popular, especially among schoolboys, during the late 19th century. Carroll originally wanted to put the entire poem in reversed form, but inevitably decided on just the first verse. In a periodical Carroll wrote at the age of 23 to amuse his friends, he provided explanations for all the nonsense words in the first verse, all of which vary from Humpy Dumpty's versions later in the book.
Later work in physics confirmed that there would be dire consequences for the Alice that entered the Looking-Glass world. It is clear that she remained herself when she entered, because she has to hold the book up to a mirror to read it. In this case, her normal matter would clash with all the anti-matter around her, and there would likely be an explosion. This is humorous in light of her speculation about Looking-Glass milk, which is most likely not at all nutritional.