I LOVE belts, they can truly change the simplest of outfits, and this outfit…is perfection! LOVE the red shirt against that gorgeous belt, simple accessories (especially those sunnies!) and velvet (?) pants. xx
I think he's Milan Vukmirovic and he designs for Trussardi.
The red shirt is from the Trussardi collection 2010! And he was also photographed once by Scott for wearing a powerful necklace against a simple outfit. And the necklace was also from Trussardi.
If my guess is correct, he's a type of designer who sometimes designs what he wants to wear but mixes up with other clothing to get that wow factor.
Like how he picked out his own red shirt and own necklace, but still wore it so beautifully with other clothing. And the belt, not too sure if it's YSL but the Trussardi 2010 collection does have printed belts in beautiful colours.