The sister represents the adults, and Alice represents children. Children are innocent, imaginative creatures, that all adults adore. Adults wish they could be as innocent and pure as children to escape from the intricate world, but that's no gonna be possible. So the childlike thoughts can only remain in their dreams and memories.

The Queen is rather ironic in this book. All she knows is to sentence people to death, regardless of the truth and justice.

This reminds me of another book The Hunger Games. The act Alice describes is a key move in that book, which tells a story of rebellion and revolution.

The Queen and the King have absolute power in the Wonderland. Everything they do must not be doubted no matter it's right or wrong. Actually, nobody will question their behavior because they have got used to their savage acts and nonsense.

The Hatter is a humble man. All he can do is to knee down to the King even if there is nothing guilty with him. It shows the relationship between those in power and those humble.