The first canto sets up the satirical statement that Pope is making about 18th century fashionable society. The first two lines,
What dire Offence from am'rous Causes springs, What mighty Contests rise from trivial Things
suggest that the poem references society's tendency to embellesh and exaggerate relatively small infractions of its rules and to hold grudges for such infractions for a long time. Indeed this particular event, the impish cutting of a small lock of hair, springs of a true story from the 18th century. While most of us can understand how some things are blown out of proportion, Pope, in Canto One, sets this event up as the cause of the conflict and as a way to reveal the behaviors of the individuals involved as vain and trivial.
In Canto Two, society's infatuation with physical beauty is revealed as the author pens line after line comparing Belinda's beauty to that of a divinity and describing her lavish garments, jewelry and surroundings. The point being made is that this society is vain and materialistic.
In Canto Three, the behaviors of this society are examined. The important pursuits include card games and gossip, which are both taken very seriously. In fact, Belinda has sylphs which help her by protecting her cards. This insinuates that members of fashionable society could not function without a myriad of helpers.
Canto Four, Belinda reacts to the "rape" of her lock of hair. The use of the word "rape" indicates the level of reaction that ensues this prankish act. Instead of laughing it off as a joke, Belinda becomes enraged and incapacitated, unable to act without her army of sylphs. Her ladies react similarly, treating this as the ultimate act of sabotage and betrayal.
Finally, after a battle reminiscent of epics such as the Aenid, a truce is reached. After the tragedy, Belinda is happy with a bit of fame and martyrdom, as indicated by the lines
This Lock, the Muse shall consecrate to Fame,
And mid'st the Stars inscribe Belinda's Name!
Belinda is not urged to peace by fairness or practicality, but by the promise of her name in the heavens.