At the end of the second act, when the mistaken identities have all been revealed and Gwendolen and Cecily have stormed off, furious about the lies that they have been told, Jack and Algernon are left behind to plan how to fix the situation. However, rather than take things seriously, Algernon begins to eat muffins at a frankly alarming rate. Jack comments on the absurdity of Algernon's actions:

JACK. How can you sit there, calmly eating muffins when we are in this horrible trouble, I can't make out. You seem to me to be perfectly heartless.

ALGERNON. Well, I can't eat muffins in an agitated manner. The butter would probably get on my cuffs. One should always eat muffins quite calmly. It is the only way to eat them.

JACK. I say it's perfectly heartless your eating muffins at all, under the circumstances.

Algernon's response shows his disregard for the seriousness of the situation in which they find themselves. He is only concerned with his own pleasure and preference. Indeed, this dialogue leads into a heated discussion, not of their engagements to Gwendolen and Cecily, nor of the trouble they have caused with their false identities, but rather of the etiquette of eating muffins, or eating at all when in times of stress. By having the characters discuss something so superficial and self-oriented instead of the actual details of the mess they are in, Wilde is commenting on the vanity and absurdity of the characters and satirizing the flippancy of the upper class

At the end of the scene, after diverting slightly to determine whether Jack or Algernon should be rechristened as "Ernest" to satisfy their respective fiancées, Wilde has them return to the muffins. The entire act closes with Algernon announcing that he will stay until the muffins are gone. The absurdity of the focus on the muffins in this moment, the height of the dramatic tension in the play, is not only humorous (this scene is usually the one that elicits the most laughs from audiences, in my experience having seen the play performed several times) but emphasizes the satire of the piece, commenting on the morals of the upper class and their habit of prioritizing etiquette and manners above all else, even in times of emotional distress.