Yeah I don't really get it either. Why not sell the sensor on its own so that I can wear it on anything I want? What's the added value of having it sewn to your jacket? It's not like it's particularly small or discreet.
This has been a few years in the making. The actual innovation here is the new gesture-sensitive fabric being woven into the denim, not whatever it's talking to.
They can’t really, the thing Jacquard was attempting was weaving an interactive surface into a piece of clothing. The clip on sensor is just a little glue interface that takes the sensor information from the cloth and extracts gestures and send them to the phone.
because then google can't quietly change the design of future versions to monitor you with more than they can get out of the touch sensor