Security is another aspect. Any feature that involves user data needs to handle it securely. If the feature requires user login, then encryption and secure authentication methods are essential.
Monetization could be a consideration too. Do they want the feature to generate revenue? For example, a premium feature for advanced reviews or a subscription-based movie library. jex movie website link
Another angle is mobile compatibility. If the site is responsive, the feature should adapt to different screen sizes. If they're planning to release a mobile version, the feature should support a good mobile experience. Security is another aspect