"I'm going to direct now," Gurinder Chadha announces. "Why don't you come over here, Mr Cameraman?" The cameraman mutely obliges.
"Now, you all look like I'm saying something intelligent." There is a muffled laugh from the teenagers sitting in front of her. "We call this the over-the-shoulder noddy" - another laugh - "and it's the most useful shot. If I start talking rubbish, you can just cut to that shot."
Chadha, director of Bend It Like Beckham and Angus, Thongs and Perfect Snogging, is providing impromptu directorial tips as part of a workshop with students from St Charles Catholic Sixth Form College in west London.
To mark the release of her latest film, It's a Wonderful Afterlife, the film and media studies students have been invited to a workshop in London's Leicester Square organised by Film Education. It is the educational charity's hapless cameraman whom Chadha has been casually directing.
The half-hour session allows the writer-director to provide practical advice for St Charles's putative actors and directors. So teenagers ask whether scenes are shot chronologically, for example, and how continuity is ensured between takes.
But they also ask questions about Chadha's career path. "It's just hard work, really hard work," she tells them. "After my first film, I couldn't get another film off the ground. I thought about giving it all up. Then I thought, 'I'll give it one last go.' And that was Bend it like Beckham."
Eighteen-year-old Riearna Walters is inspired by the tale of near-failure. "It just shows that your drive is what actually pushes you to success," she says. "No matter how many times she failed, she still continued."
Riearna eventually hopes to become an actress. "There are always ups and downs," she says. "But if you're determined and you know exactly what you want, you will get there."
Chadha is best known for bringing everyday scenes of British Asian family life to the cinema. It's a Wonderful Afterlife is set almost entirely in Southall, the west London suburb where she grew up.
"I set out to show more people like me on the screen, to show Britain in its diversity," she tells the students.
"But cinema is an international language. We all fall in love in the same way. We all fall out of love in the same way. We all like to be scared. We all have the same emotions."
Suraj Pillai, St Charles film and media studies teacher, hopes that Chadha's big-screen versions of ethnic minority life will resonate with his multicultural students. "They need role models who have similar backgrounds, similar experiences and who are sometimes also marginalised," he says.
Riearna agrees. "I'm black Caribbean," she says. "So I don't want to just see the stereotypes of my culture: violence, gun crime. It's very important to portray the parts of your culture that people don't see every day: your home life, the food you eat."
As the workshop ends, Chadha swivels round in her chair to face the students head-on.
"What we need are British filmmakers who look like you," she says. "I'd like nothing more than to sit in a cinema audience and watch a film that you make."
STUDY BARD NOT BRAD
Hollywood tends to assume that a romantic comedy needs only two main leads and their sidekick best friends, Gurinder Chadha says.
But A-level English taught Chadha that this is not the case.
"We could learn a lot from Shakespeare and his romantic comedies," she says. "You've got best friends, servants, colleagues. Their stories are all built into the main love story. It's very much part of the fabric of British society."
Chadha prides herself on bringing Britain's Asian community to the big screen, but she believes that her films transcend cultural boundaries.
Her latest film, It's a Wonderful Afterlife, tells the story of a British-Indian mother keen to see her daughter married. "That film could be set in Italy, Greece, Africa ...' she says. "Every mother in the world wants to see her daughter married."