[MWil]

wouldn't a simple motion-detected: yes flag or motionLastDetected:XX:XX:XX be less invasive?

[pdenya]

As the article states, it's helpful for others to see whether or not you're on a call or eating or whatever else.

[ericbieller]

There's also a personal element. It's nice to see the faces of the people you work with throughout the day. Certainly has helped to create a tighter social bond on our team.