Esther is a complex figure, but basically she incarnates the Jewish people.
The Jewish people is always described in the Bible as having the characteristics of a woman.
Sometimes the allusion is purely mystical—for example in the Song of Songs.
But aside from mysticism. the recurrent image in the language of the Prophets is that of the bride, companion, wife of God.
Marital symbolism, as found in Hosea, Isaiah, Jeremiah, and Ezekiel, is one of the most striking features of biblical prophecy.
It has its roots in what the mystics would later call Knesset Israel, the community of Israel, the mystical unification of the source of Jewish souls, which collectively forms the interlocutor and the "wife"of the Divinity.
The entire history of the world can be seen as a marital relationship, a more or less successful marriage of love (depending on the era) between God and Israel.
Esther is the main figure of this story, but not because she is a heroine.
Rather, she represents the Jewish people as a whole.
The Jewish people are represented as a woman because she has two functions.
The first is the function of love: This is what the world should give to God.
The second is to preserve the home.
Home can be a specific land or the whole world. but in any case women are always defined as "the pillar of the home."
She watches over the home both in daily life and on the cosmic level.
In a certain way, the whole universe is feminine.
It is instructed to fructify, and it must undergo suffering in order to create.
This is the definition of the world itself.
The world is the womb of reality, the place where things are born.
This dual feature of passivity and creativity characterizes Esther's attitude.
At flrst she undergoes events and refuses to act.
Then, when she does act, she changes the course of history.
–Rabbi Adin Steinsaltz
From The Seven Lights by Rabbi Adin Steinsaltz