I think people who know nothing about "Grey Gardens" will still get the point of the scenes: that the two of them will become isolated, odd, and alone as they grow older together.
Oh yeah, they'll get the spinster angle. I guess it'll depend on how much of a GG send up (or rip off) it is. Costumes, sets, background music, etc... Judging from the pics they're going for a real
Grey Gardens feel. That's what I think will go over some people's heads. I wouldn't be surprised if it breaks down along generational lines.