Why did she refuse to come? She was lewd - this is why she made the women's party in Beis ha'Malchus!
Rashi citing Megilah 12b #1: Tzara'as came on her.
Torah Temimah citing Megilah 12b #2: Gavri'el came and made a tail 1 on her.
Malbim: He wanted her to come to show that she is queen only due to marrying him. She will wear the crown (Ohr Chadash - royal clothing) only in front of him; he called her via Sarisim, and not via all the royal officers. Also refer to 1:12:2:1. She persisted in her claim that he is king only due to her.
Ohr Chadash: 'Tail' represents the heavy nature of an animal. Gavriel made her nature heavy, so she did not want to move.
He asked for "Vashti ha'Malkah" (11). Why is she called here "ha'Malkah Vashti"?
Vilna Gaon, Malbim: He said "Vashti ha'Malkah" - she was a commoner, and became queen via marrying him. She said "ha'Malkah Vashti" - I was queen (I inherited kingship from my father) even before I married you.
Why did he get so angry?
Torah Temimah citing Megilah 12b: She sent to him 'stable boy of my father 1 ! My father would drink as much as [the bigger drinker among] 1000 people and not get drunk, but wine gets you drunk!' 2 (Chasam Sofer - she said this in Babylonian. The servants who relayed the message did not understand it. This was why Achashverosh decreed that a woman must speak the language of her husband (22).)
Ohr Chadash citing Esther Rabah 3:14: Initially, she hinted - if they see that I am beautiful, they will desire me, and kill you! If they see that I am ugly, you will be disgraced! He did not accept this. Afterwards, she insulted him.
Why does the verse mention Ketzef and Chemah?
Vilna Gaon: Ketzef is exposed anger, like Ketzef (bubbles) on water. Chemah is anger stored in the heart. The Gemara (Megilah 12b) answered, due to her words of disgrace. The messengers told only the king; he showed anger only for her refusal to come.
Malbim: He showed anger only for her refusal to come. Inside, he was angry that the entire purpose of the party - to show that his kingship is due to himself, and is unlimited - failed.
