(First off, let's get the full disclosure bit out of the way: I think closing questions as "too trivial" is not a good overall policy, for reasons that are largely irrelevant to this question. I'm not arguing we change that policy, but it does color my opinion a bit, so I wanted to get it out in the open.)
tl;dr: Given that site policy is to close trivial questions, and shopping questions are off-topic on most of SE, I think there is plenty of justification to close some of these identification questions as one or the other of those. But I would suggest we err on the side of leniency -- make sure the question is well written and clear, but prefer to leave it open unless it's clearly just useless minutia.
The main reason that I am skeptical about closing all questions like the ones you're asking about is for two reasons:
Who Else Knows This Stuff?
First, the justification for closing trivia questions seems, from my previous discussions, to be motivated primarily by the fact that we don't want to be "just another IMDB" -- that is, we don't want to be a repository for facts that can already been found elsewhere. This includes things like actors personal info, filmographies, cast/crew/etc information, etc. I can understand why those questions seen like a bad idea, so the fact that the community wants them closed is understandable.
But many of these "trivial" questions like you're asking about are things that just aren't found anywhere else, and require time, research, and a familiarity with the work in question to answer. That seems to me like exactly the kind of question a site like this was built for. Not every question on the site is going to be a masterpiece of cinematic analysis; some of them are just going to be short, simple, easy questions. I think that's OK, as long as the question and answer are interesting to someone. (You would be amazed at some of the "utterly uninteresting minutia" questions on other sites that asked more than once!)
Don't Judge The Question By It's Answers
The other problem I have with being strict on closing these questions is, it's entirely possible that the item being asked about is significant to some part of the film, even if the OP didn't know it. They may have just seen a weird looking bong and wondered what it was, when the prop might have turned out to be a carefully planned way to express the distinction between two characters.
We wouldn't know that until someone came along and answered it. And that's the kind of very interesting answer I think would make a good addition to the site, even if the question that got it here wasn't so awesome. And really, it's the answers we're interested in.
