I love watching audiences react to films. As anyone who has watched in different cinemas with different audiences knows, the viewing experience also varies depending on the people you're with. A Makati office weeknight audience at Glorietta laughs at different scenes from a Sunday afternoon family crowd.
When showing films to my various classes I watch them and note their reactions. It helps me tailor my subsequent lecture to their level of understanding.
Filipino film critic Noel Vera showed the Lino Brocka classic "Insiang" to American students and writes about their reactions. Interesting questions, especially the one about Filipinos eating with their hands.