At any point while completing a review, you can stop and flag an issue. The issue can then be linked to a specific review slide. This allows other users completing the design review to see what issues have already been brought up on a particular slide.
Click on the ‘Issues’ button on the review slide you would like to link the issue with. Start typing the title of the issue and then select it from the list. That issue will now be linked to that review slide, and will appear on the issue list page when filtering issues for that design review.
You can also create a new issue by typing into the ‘Create Issue…’ field and giving the issue a status.
Similarly, to remove the issue from the slide, click the ‘Link Issues’ button, and then click the ‘x’ to the left of the issue title to remove it from that slide.