Final answer:
The lines are satirical because they reveal the sylphs' excessive concern over a trivial matter.
Step-by-step explanation:
The lines at the end of Canto 2 in your question are satirical because they reveal the sylphs' excessive concern over a trivial matter. Satire uses exaggeration and humor to expose human weaknesses, and in this case, the sylphs' anxious and trembling anticipation of an event that turns out to be trivial highlights their folly. The use of exaggeration in these lines mocks the sylphs' exaggerated reaction to the situation.