Thanks.

It seems that I was somehow in the YARM view for the exact copper mine I was standing at.
I'm not sure how I accidentally triggered that, and usually that menu is a little cumbersome seeing as I play with a Steam Controller.
Though it looks like there might have been some sort of YARM ...

I was playing factorio with 2 friends on a MP (headless) server when all of a sudden my in game player/sprite disappeared, I have no inventory and cannot move or do anything.
The server is being hosted on a DigitalOcean 2 Core, 2GB Ram droplet.

Bringing up my inventory shows no slots altogether ...