To Choose Who To Send The Game or Story To.
So when you for example create a story when you click or tap share then add an option if you want to share it to like the is a search search bar to search a nickname and avatar picture.
Victoria Chan commented
I have used the project ID option for it is a pain to use and too many characters to copy down and type in, and I'm a grown up. Kids will really struggle with that. Alternatively it will be nice to be able to search for games by users.
The golden spyglass icon is there so you can enter in project IDs from stories and games coded by your real life friends. Thanks for the suggestion!