The 2.4GHz Zigbee antenna is one of the first things that we can see on this CT scan made by Lumafield.

Zigbee is a low-power, wireless communication standard designed for reliable, cost-effective, and energy-efficient data exchange. It is widely used in smart home, industrial, and IoT applications.

 So what makes the light bulb smart? An ability to wirelessly connect with the hub and communicate with it.