This is a genuinely interesting problem, and one more commonplace than one would hope to see. What you are trying to do is second guess the intentions of the interviewer and as you cant really do that even in a F2F let alone a telephone interview (as devoid of clues as they are) I suggest you take a foot forward approach.Right up front take charge of the agenda and qualify do they want to talk through your technical skills, your business skills, or both? State clearly that you bring both and need to know where to orientate your focus so they get the information they need.