It's Marcel Floruss from the blog One Dapper Street showing how to wear a blazer with jeans and oxfords. He's wearing a pair of Armani jeans with a blazer from Tommy Hilfiger and a pair of oxfords. Get more info on his look and check out more pictures on his blog. This is a nice and casual yet highly stylish look.
Here's how you can copy Marcel's look. This features a Hilfiger blazer, Armani jeans, brogue shoes and an Armani bag. Shirt is solid where Marcel is wearing a print shirt. Shirt is from Armani.