In episode 4 you show the screen preview bottom right. How did you do this?
A beginner-level tutorial for making a top-down adventure game in PICO-8. · By
That was actually a cart I created specifically to demonstrate how camera() works. So I just made part of my _draw() function manually draw a little screen preview in the corner based on where box was. It looks cool, but it took some work to create. I hope that answers your question. (Let me know if you have more.)