The above trailer is for the play performed at York Theatre Royal, York, England in 2011, NOT the BBC television film released in 2005, which this DVD contains. So the producer and actors that appear in the trailer are not the ones in the film. So the trailer is not relevant to this DVD.
I haven't seen the play, so I can't comment on it, but apparently it did not fair well with the critics. But I HAVE seen the film and it is a delight, well produced and with fine acting. So I highly recommend it.