The L3, just like all other recent bitmain hardware, has a controller embedded on the ASIC.
You just plug the power in, connect the network port to your switch using a standard utp cable and it's done. You only need a laptop or PC to surf to the webGUI to set everything up.
Any laptop, desktop, phone or tablet will do, as long as it's able to connect to your network and open a browser.
Once the setup is done, you don't need the laptop/desktop/phone/tablet/server/thin client any longer.
You are NOT using the laptop/desktop/tablet/phone to mine, only to setup (chose the pool, set some parameters,...)
I've had some misconceptions about how all that works. Thanks for clarifying this Mocacinno.