How should I set up tasks for client review?

There is no single right way. Glance shows whatever matches the visibility you set, so the choice is about your process:

• Dedicated subtask: create a subtask named for the deliverable, attach the final version there, and let only that subtask reach the client. Your internal task stays separate.
• Parent task: use the parent task as the review surface and attach the final deliverable to it.
• Status only: flip any task to your review status when it is ready, and back out when it is done.