It is a preload smart scan beacon. A light DOES blink on them every now and again. But they don't have cameras, mics or shock sensors in them. Just a bluetooth antenna and transmitter, and 5 batteries to keep it broadcasting for 5 years. Most of the beacon is battery.
In a week or two, you'll associate a package car and a load ID with those beacons at the start of the sort. You'll scan packages you're about to load into a "queue". If you walk into the wrong car with your "queue", the scanner will make a loud, annoying long beep. Right car, short beep, and the packages will be associated with the car. On average, they cut misloads by 2/3rds.