The original article contrasted Facebook with earlier online communities such as Fotolog, MySpace and Hi5. It described the expansion from a university-oriented service into a much wider communication channel.
A window into everyday life
The glass-house metaphor concerned the details visible to other people: a relationship status, an event somebody planned to attend, a holiday announcement or a short statement about their mood.
A contact did not need to meet someone regularly to receive fragments of that person's life. The author saw that as a significant change in the relationship between private experience and public presentation.
Which parts people choose to show
The article noted how often updates presented happiness, excitement or anticipation. That did not necessarily mean the whole life behind them was equally visible.
A feed is shaped by what participants choose to post. The reader sees selected moments rather than an uninterrupted account of everything happening to another person.
Old acquaintances return
Another theme was the reappearance of people from earlier periods of life. A service could put former classmates, friends or other contacts back into someone's present, even when the relationship had naturally become distant.
The author found that ability striking. Renewed contact could be welcome, but it also changed how easily different parts of a person's history were connected.
Updates can produce real reactions
The source used changes to a relationship status as an example of something that could trigger calls and questions from contacts. A small interface action could therefore have effects outside the website.
The useful point is to think about the actual audience and likely interpretation before posting. An update that seems clear to its author may convey something different to another reader.
Reading the metaphor today
This is commentary from the service's earlier period, not a current statement about its size, leadership or privacy controls. Its claims of universal participation and neatly measured degrees of connection were rhetorical, rather than proof that every person experienced the network in the same way.
The related messaging privacy article considers similar questions about who is on the other side of a connection.