Try listening to the American English pronunciations for professor (you may want to try following it with at). If you compare British to American English, you'll notice that the final /r/ sound is pronounced in American English - most dialects are rhotic - whereas in British English, the final "r" in "professor" is usually unpronounced.
When Amy Chua says "professor," she pauses for a moment on the /r/ sound, and I think this is what you see as a pout.
Also: Listen to law school (or the separate words law, school, where you'll hear more of the diphthong in "law"). As an American English speaker, I don't notice anything surprising about Amy Chua's "law school" pronunciation. It seems to me that she rounds her mouth a little toward the end of "law" and then more at the end of "school", which I think makes sense because they have rounded vowels.