What exactly are Minikits supposed to be? And what’s the meaning behind their design?

I know what Minikits do in the LEGO games, but I’ve always wondered what they’re actually supposed to represent in-universe. Are they supposed to be some kind of battery, survival kit, piece of equipment, or something else? And what’s the reasoning behind their actual design? They’re basically a gray cylinder with a red light, a green light, and an antenna. Why do they look like that? Does each part have a specific purpose, or was it just designed to look like some kind of sci-fi device? Is...