Williams' email requesting me to attach an academic writing

As the title suggested, I recently received one email from an admission officers asking me to provide extra academic writings.
I hope this email finds you well.
The email is like this:
I work in the admission office at Williams College, and I’m reaching out to ask if you’d be able to send a paper you wrote recently for a humanities or social studies class. What we’re looking for is an academic paper, not a creative piece or poem. A graded, recent paper for English or other humanities course, would really great. Would you be able to reply with the paper as an attachment in the next couple of days? If this timeline poses a challenge, don’t hesitate to let me know, and we can adjust it.

Thanks in advance, and I look forward to hearing from you.

That probably is a positive sign. I would conclude that you are under serious enough consideration that they want to make sure that you are capable of the level of writing you would need to do for classes at Williams. I do not know why you are being singled out for this. As far as I know, most domestic applicants are not asked to send additional writing samples. Maybe you are an international applicant for whom English is a second language? Or maybe there is a inconsistency between your writing on different items they can see from your application. At any rate, they felt they needed to see more writing in order to be able to make a decision on your application. This means they still are considering your application.
Good luck!

@Xuedingedemao : With a 1540 SAT & a 3.95 GPA (as you posted in another thread), I find this request perplexing.

P.S. My best guess–and it is only a guess–is that your application essay somehow raises concerns when compared to your stats.

I feel like my essays should be at least OK since I was accepted by many other schools( though not as competitive as Williams), and I have edited my personal statement many times and a could (not a lot) times for Williams supplement, so I hope my application is good.

IMO there isn’t much to think about…send them a recent graded academic paper.