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.
Another thing to consider is the target audience. Who uses the website? Casual movie viewers, critics, or a mix of both? The feature should cater to their needs. For example, if it's for casual users, maybe a social feature is better, while for critics, in-depth analysis tools could be more useful. jex movie website link
Since they mentioned a "movie website," perhaps they're missing some core functionalities. Let me think: typical movie sites have movie listings, showtimes, cast information, reviews, ratings, trailers, and similar movies. Maybe they want to add something like a personalized movie list, a forum for discussions, or a way to track watched movies. Another angle is mobile compatibility