I’ve seen a few job listing like this in the past but never quite as vague!
It’s really annoying, I can understand that a recruiter doesn’t want you to apply directly and cut them out, but how can you be expected to tailor your portfolio/covering letter to suit the company if you know nothing about it? Most listings at least share the sector so you can take a gamble on that.
I’d call the recruiter and try and find out a bit more about the company if you possibly can, otherwise you would just have to apply with a generic industrial design portfolio that shows examples of what they have said and hope for the best!