I'd say it's because we can see a lot of waistband as well as shirt and tie through the space the jacket presents to us at the bottom.
Still I think the outfit is very very nice, the jacket just has an unusual cut/closure.
Derek, I like the jacket and the classic combination of blues and whites.
Not too sure about the shoes and I'd show a bit less PS.
PS: Tell Mrs. Derek to burn that blanket!
Lady Gaga loves Derek's rug...