What does Pope's "The Rape of the Lock" reveal about 17th century England?

First of all, it is important to acknowledge that "The Rape of the Lock" was actually written in the early eighteenth century. Secondly, we need to remember that the poem was written for a specific audience. Pope intended his mock heroic epic to be read by the wealthy upper classes, the creme de la creme of English society. He wanted his target audience to read the poem and recognize themselves and the people they knew.
Pope holds up a mirror to the English aristocracy and lets them take a good, hard look at themselves and how they behave. What they should see in the reflection is far from flattering, to say the least. The upper classes in "The Rape of the Lock" are presented as shallow, vain, idle, and obsessed with trivia. In the character of Belinda—based on a real lady of quality by the name of Arabella Fermor—we have an unforgettable portrait of vanity and superficiality. Belinda's Bible, sitting uncomfortably on her crowded dressing table, along with all her potions, powders, and beauty creams, is a striking symbol of a society in which religion is all just for show; what really matters is personal appearance and what other people think about you.

First, we should note that Alexander Pope's "The Rape of the Lock" doesn't tell us about life for most people in England of the period, but only about the lives of the very wealthy and fashionable. It doesn't describe working conditions for peasants or craftspeople or even the lives of the servants who keep the court functioning. In a sense, though, this absence itself is informative in that it gives us a sense of the distance between the lives of the wealthy elites and most of the population.
Next, we get a sense that this is a very status conscious society, in which maintaining "face" or appearances is very important. 
The society has a strong element of gender inequality and double standards concerning sexual conduct. Men gain status by promiscuity or sexual conquest and women lose status by it. 
As a satire, it comments on what Pope exposes as the vanity and worldliness of the upper classes.