What's cool is that the exchange of information is actually a two-way affair: The desk uses its WiFi connection to pull in information from Fitbit (think: steps taken) and then display that on the table's built-in touchscreen. Meanwhile, of course, the desk knows when you're nearby, as it has motion sensors built in (obviously, too, it can tell, based on the height of the desk, whether you're standing or seated). Using this information, Fitbit can calculate how many calories you've burned while working. This is especially nice because Fitbit's fitness trackers couldn't otherwise tell how many calories you've burned while standing still; they only know how many steps you've taken. So, if you're trying to weigh your Fitbit activity against your daily food intake, you might be pleased by all the "bonus" calories you burn as a result of merely standing around.
If you happen to be one of the few who bought a Kinetic desk during its first production run, you'll receive these latest features via a software update (again, the built-in WiFi comes in handy for this sort of thing). And if you didn't, well, plenty of other fitness trackers can estimate your daily calorie burn as well -- and for a fraction of the price.