With share for review, you can ask someone for a specific kind of feedback, even if they’re not signed in. Here are the three things you can do:
Allow reviewers to leave comments on board items
Starring an item is the more or less the same as giving it a thumbs up (It’s really useful if you’re just needing a yes or no).
If you happen to be on the board at the same time someone is starring items, you’ll see notifications pop in the top right, like this:
Allow them to download files on the board