During Nintendo Treehouse Live, Junichi Masuda showed a video of how trading works in Pokemon Let’s GO Pikachu/Eevee.
When players wish to trade or battle with someone else, they’ll be given an option to do that with someone over the Internet or someone nearby. If it’s done with someone via local wireless, both trainers will have to enter the same link code to find each other.
Then, the trading sequence works similarly to previous Pokemon games. Here’s a look: