A useful brief is specific
Describe your palette, type direction, audience and offer. “A warm editorial welcome for a small-batch coffee brand, with an oat background and a quiet right-side entrance” is more useful than “make it convert.” Include the exact offer and the email-consent wording you want reviewed.
Keep creative review in your hands
Review a generated artifact in desktop and mobile preview, ask for a revision, then approve that exact version. A new draft does not automatically replace a published form. The design can change while signup collection and game behavior stay consistent.
Test the whole interaction
A good-looking first frame is only the beginning. Exercise the game, empty and invalid email states, consent, submission failures, success and closing behavior. Private on-site previews let you check the design against the real storefront without creating subscribers.