Octoprint doesn’t stream gcode from some other computer to the Arduino. You use the Upload button to copy the gcode file to the Rpi and then Octoprint streams it locally from the Rpi. One of the things I like about Octoprint is that the UI is web based. No need for VNC. There’s even a plugin UI named touchUI tailored towards small screens.
Reply To: Dave's Mobile MPCNC