Hehehe okay so in Let’s go Pikachu/Eevee in handheld mode, there’s always a little green circle with like two people in it on the bottom right. It’s been so long and I still haven’t figured out what it means. This only exists in handheld, and I can’t select it. What’s it mean?
It's how you play co-op. Here's the details.
Hope I helped!