We've recently upgraded our proofing modal which allows users to add a proof to an action card. It'll be easier than ever to understand exactly what items you can proof in Hive, and how to streamline the uploads.
If you don't see the Proofing & Approvals section of your action card, you'll need to first visit the Apps page (accessible via left hand side bar). From there, toggle on Proofing & Approvals.
Once the app has been enabled, you'll now see the Approvals portion of your action card.

From there, click "Add proof," and you'll be able to choose a proof addition from one of three places: File Upload, Email, or Link.

You can also drag and drop the items into the proofing modal if that's easier.
If you choose to add a file from the file upload, you'll be able to select a single file or multiple files, and choose exactly how you want to view the items (folder, combined file, or individual subactions).

When you add a proof by email, you'll be prompted with a custom email address that you will send your proof to.

Finally, if you want to upload a link, you'll be able to select either a Live Website, Page Snapshot, or a Hyperlink.

Happy proofing!