Executives at the brand signed up 17-year-old Alex for their latest national advertising campaign, shot by Mario Testino.
Scroll down to see a behind-the-scenes video
No sibling rivalry here: Emma Watson poses with her younger brother Alex for Burberry's Spring/Summer 2010 campaign
It is the second campaign for Burberry that the 19-year-old has taken part in, and looks as though it will be as successful as her first.
Also appearing in the campaign are George Craig, frontman of indie band One Night Only; Matt Gilmour, the son of Pink Floyd’s David Gilmour; and model, Max Hurd, a grandson of the former Foreign Secretary, The Lord Hurd of Westwell.
The adverts feature three of the Burberry fashion brands, Prorsum, London and Brit, all designed by Christopher Bailey, the current British designer of the year.
But the aspirational high-fashion brand which has undergone a renaissance in recent years after the iconic print became a favourite among 'chavs' is hardly affordable for most people Emma's age.
Spoilt for choice: Emma cuddles closer to Matt Gilmour, the son of Pink Floyd’s David Gilmour, while Max Hurd (r) - grandson of former Foreign Secretary Douglas Hurd - strikes a poseA woman's classic trenchcoat starts from an eye-watering £625, and the same goes for the pricey menswear modelled by Emma's equally youthful brother.
Emma, best known for her role as Hermione Granger in the Harry Potter movies, said during the shoot: 'Today is really special for me in a number of different ways.
'It's so nice to see Mario and Christopher again. They also shot my brother in the campaign.
'He's having such a great time. He's so psyched.'
Magic touch: Emma casts a spell over George Craig, frontman of Yorkshire band One Night Only
Iconic images: Mario Testino shot the ad campaign for Burberry
It is the first modelling assignment for Alex, who has also appeared as an extra in Harry Potter And The Order Of The Phoenix, but he has now been snapped up by London model agency Storm.
He said: 'It's such an honour to be a part of this. It's really exciting.'
Christopher Bailey, Burberry's chief creative officer, said they were thrilled to be working with Emma again.
Make him carry: Alex poses with three Burberry bags, as Emma goes for a casual but sophisticated look
'We've worked again with Emma Watson who has a classic, effortless beauty and is incredibly talented,' he said.
'We wanted this kind of eclectic but very cool crowd of people.'
He added: 'We always talk about how much fun we have making these images and I wanted to capture some of the excitement that you feel on set when all these different creative attitudes and personalities come together.
'Mario has shot these as both stills and video so we can share some of that energy with a wider audience.'
Classic wear: Emma, Max Hurd and George Craig wear iconic designs by Burberry in the pictures
Burberry Spring/Summer 2010 campaign