When a space's live edits are unlocked, you'll be able to see the avatars of the team members that are currently viewing the space. This is shown at the top right corner of the page. Anyone can start editing the space, but this works on a first come first served basis. When an editor starts making changes, editing is temporarily locked for all other viewers in that space. Once the editor's changes are saved, editing is released and made available to any of the viewers that want to start making changes.