Starscream bristles at Megatron's tone and the fact that he hasn't gotten a satisfactory question as to this mech's identity, because his logic circuit is still struggling to process the possibility that he might actually be Megatron. Just not his Megatron. Which carries an awful lot of implications that he's not sure he has the processing power to dedicate to sorting through right now.

But, for once in his life, he recognizes that petulantly belaboring the point purely for the sake of getting his way isn't really getting to get them anywhere, he scoffs, "Starscream. Of the Decepticon scientific corps. And one of Megatron's most trusted advisors."

That is technically not in his job description, but Starscream feels like he at least earns that title by virtue of being Megatron's conjunx socia.