In this passage Rebbe Shimon is talking to a soul from the spiritual Garden of Eden.

Rebbe Shimon said: I certainly know that there [in the lower Garden of Eden] you are dressed in the glory of a body that is pure and holy.

This body of souls is a body of light that is made from the spiritual light generated by mitzvot performed in the physical world.

Was there ever something similar to this dress in this [physical] world? That is a person who appeared in the same body like that which you stand in up in the spiritual worlds.

Rebbe Shimon is interested to know if there were people in the physical world who were so righteous that their bodies were an extension of their refined spirituality. Esther…put on the same likeness as that of the spiritual world…

He answered him: two young people who were dressed among us asked this question of the Head of the Academy after they had suffered remorse in respect of a sin that is not fitting to reveal. They asked this of the Academy Head, and he answered them, saying that there was such a thing in the physical world. From where do we learn this? From the verse: And it came to pass on the third day [of her fast], that Esther put on her royalty [literally "malchut"] and stood in the inner court of the king's palace opposite the king's residence… (Esther 5:1). This means that she put on the same likeness as that of the spiritual world, because the word "royalty" refers to the spirit of holiness.

The [sefira] of malchut/royalty is from the heavenly realms and [even though it is in the physical realm, it] captures the spirit of the atmosphere in the higher [spiritual] realm. This [spiritual form] is what Esther dressed herself in.

After fasting and praying for three days, Queen Esther had purified and refined her physical body to the extent that she was worthy to receive spiritual garments even in physical reality. Her beauty must have been a wonder to gaze upon, and this explains why she found such favor in the eyes of King Ahasuerus.

And when Esther entered in front of King Ahasuerus and he saw this outer appearance of spiritual light, her appearance was like an angel of G‑d. Then [when he saw her] his soul left him momentarily.

Mordechai was also the same, as is written, And Mordechai went out from the presence of the King in royal clothes (Esther 8:15). This was literally the clothing, or external appearance, of the sefira of malchut [of Zeir Anpin], the likeness of that higher world. That is why it is written that the fear of Mordechai had fallen upon them, (Ibid. 9:3). They feared Mordechai [because of the awesomeness of his spiritual appearance], not Ahasuerus.

[Zohar, parashat Shelach Lecha 169b; translation and commentary by Simcha-Shmuel Treister]