I shoot video. I've had a recent spate of clients who all do the same thing.
Me: What are you looking for, specifically?
Client: Just follow your own vision. You will know best.
This I think almost always a huge red flag, but really all you can do is plug on and hope you can get into the ballpark if they're stubbornly telling you nothing.
What happens every time:
Client: This isn't what I wanted. Can you just send me the raw footage?
Me: Please let me know what you're after and I'll get to work on the changes.
They proceed to not send me anything and they always use what I sent originally anyway.
This is why I make sure I get paid upfront.