There's no firmware written yet for the pico like with the arduino and some other mcus. You'd have to write your own firmware for the pico and the firmware could setup the USB connection as a serial port that could be communicated to with serial (VISA). Probably wouldn't be terrible to port the hobbyist firmware over to pico's sdk but it's a bigger footprint and more work to get things like serial comms working than what's typical with arduino development.
~ Helping pave the path to long-term living and thriving in space. ~
