Albany’s greater insight into Goneril and Regan’s complete disregard for social order, familial bonds, and basic human compassion, provokes him to look to the gods and heavens above for divine justice. This parallels Lear and Gloucester’s invocation of the gods, and underscores Britain’s descent into chaos and disorder.

Albany now sees Goneril and Regan’s true colors and compares them to animals to characterize them as vicious and barbarous. Note that he states that not even a bear would hurt their “gracious” and kindly father in the way that they do, suggesting that Goneril and Regan’s cruelty is even more brutal than animal life. Goneril and Regan’s greed and senseless violence brings them down to a level of savagery that even the most lawless beasts would not descend to.

“Worth the whistle” refers to the proverb “It is a poor dog that is not worth the whistling.” Goneril uses this allusion to chastise her husband for not welcoming her when she came home; in other words, there was a time when you thought I was worth the whistle. Since she was just claiming that her husband was a “fool” unworthy of her body, it is odd that she would care that he did not welcome her home.

“Pluck” draws the reader’s mind back to Goneril’s command to “pluck out his [Gloucester’s] eyes,” rather than killing him instantly as Regan suggests. Here, Goneril subconsciously invokes the idea of divine justice: just as she had Gloucester’s eyes “plucked” out so will her objectives be “plucked” from her. “Pluck” and “hateful life” seem to be Goneril foreshadowing her own downfall.

Notice that by “my Gloucester” Goneril means Edmund. But later in this scene Albany will use “Gloucester” to refer to Edmund’s father. Because Goneril knows that Gloucester was blinded and banished to the countryside, she uses Edmund’s new title to refer to him.

“Distaff” refers to a spindle for weaving that was symbolic of womanhood. In claiming that she will “give the distaff” to her husband, Goneril emasculates him. She symbolically trades places with the master of her house by claiming the “arms” of the army and giving the spindle to her husband.

Oswald tells Goneril that her husband openly claimed that her arrival was “worse” than the arrival of the army. Even though Goneril assumes she has gained power, this Albany’s unabashed hatred of his wife and open disrespect show that Goneril has not achieved the influence that she imagines.

“Filths” here refers to the “vile,” or evil, people, and “savor” means “to enjoy” or “to delight in.” Albany continues to berate Goneril for her actions, claiming that evil people will see true good as evil and their own evil actions as good. By expressing this, Albany accuses Goneril (and Regan) of being blind to her own misdeeds against her father because of her desire for power.

Over the course of the play, Goneril has begun using the royal ‘we.’ This rhetorical move demonstrates how much power she believes she has gained, since traditionally only the ruling monarch uses such speech.

Having just heard the account of how Gloucester lost his eyes and Cornwall perished, Albany calls out to the heavens and praises them for how quickly they exacted retribution against Cornwall for his treatment of Gloucester. Albany now makes restoring the land to just authority and political order his purpose, much like Kent and Gloucester have. His belief in divine order and justice parallels the beliefs of Lear and Gloucester.

The word “mad” can be used as a verb, as it is used here, to mean “to make someone lose their mind.” By using the verb form of the word, Albany puts all of the blame on his wife and sister-in-law, accusing Goneril (and Regan) of making Lear go mad and lose his mind. Lear’s daughters have attributed his madness to his age, blind to their own role in bringing it on because of their selfishness. Albany has begun to see through his wife’s greed to get a better understanding of events.

Oaths of allegiance often include a pledge of service in life as well as death. That Edmund has pledged his service to Goneril in death only offers insight into the condition of Goneril’s plans for power. While life has positive associations and connotations, death largely has negative ones. That Edmund associates Goneril with the ranks of death suggests that she is on a destructive course with her plans for power, possibly foreshadowing more violence to come.

Presumably Goneril goes offstage to her tent so that she will be able to sit down and write an answer to the letter. She would have to have a table and chair, some paper, ink, and a quill to do the writing. This would leave Albany alone with the Messenger, so Goneril would not overhear her husband say her will take revenge on those who blinded Gloucester, mainly on Goneril's loved one Edmund.

Shakespeare often incorporates or implies stage directions in his dialogue. Goneril has no particular reason to say, "I'll read, and answer." She isn't addressing her husband, who hates her and is probably ignoring her. She wouldn't explain to the Messenger where she was going and why. Goneril is the kind of woman who would simply tell the Messenger, "Wait here!" The sentence "I'll read and answer" is intended to inform the audience why she is leaving and where she is going. She could read the letter right where she is standing, but she probably prefers to read it in privacy, since it may contain confidential matters; and she cannot answer the letter without going to her tent where she would have a table and writing materials. Shakespeare wants her gone because he doesn't want her to overhear the ensuing conversation between Albany and the Messenger, especially when Albany swears to take revenge for blinding Gloucester. He must mean he intends to punish Edmund for betraying his own father, and the most likely punishment would be death.

These six lines, except for "I'll read and answer," are spoken as an aside, since Goneril's husband Albany is standing right there. Many so-called "asides" which reveal what a character is secretly thinking were probably spoken directly to the audience, who were accustomed to this rather awkward convention.

Goneril has been making plans which she refers to as a building which exists in her fancy, or in her imagination. She wants to kill her husband Albany and marry Edmund. But if Edmund marries the newly widowed Regan, then this imaginary "building" will be torn down and she will be stuck in her "hateful life," that is, still unhappily married to Albany, who now hates her. By the word "pluck," Goneril means something like "pulled down abruptly." The elaborate "building" would come falling down upon her own head. Goneril probably did not think of killing Albany herself. She wanted Edmund to do it for her. But he would have no motive for doing so if he married Regan.

Albany overhears her say she has been "worth the whistle" and picks up on the word "worth" to express his feelings for her. 

This is a deliberate slur on Albany, her own husband. Goneril despises him because he is not as greedy and cruel as she is. She and her equally vicious sister Regan are largely responsible for the invasion they are now facing. By calling her husband "mild," Goneril really means cowardly, and she will soon tell him her opinion.