Right, it's TX-only. The article says so explicitly halfway through:

"As before, this is a transmit-only proof of concept"

I didn't notice that on my first reading.

> "As before, this is a transmit-only proof of concept"

I didn't spot that at all. Oops/Thanks!

And here I was thinking I could use a Pico as a USB ethernet dongle in a pinch /s