The vibracelet uses a vibration motor to gently stimulate the top of the wrist, which is triggered by stroking the fur panel. The fur panel functions as a textile stroke sensor by threading conductive thread strands through the fur, which when connected together is detected as a digital switch.
Conductive thread is sewn in and out of the fur and connected to conductive fabric patches on the reverse of the fur fabric, as seen in photo 2. When the threads from each patch are connected to and make contact with the threads of the other patch, this completes the circuit and behaves like a switch. See the stroke sensor instructions described by Kobakant: https://www.kobakant.at/DIY/?p=792