Strange question in a job-interview
I mentioned in the comment that it could be just a memory test, but now, with knowing a bit more of the context (it was an interview to join a bank), it could be a test about how you stick with your first decision and how you are influenced by an obvious suggestion  to change it because, supposedly, "70% people before you did", so to change the logic by which you ordered the cards the first time.

It was one of the aptitude tests, probably a variant of a situational judgement test.