It serves the same purpose as a tie clip.
As shown here by Olddog/Oldtricks
church service this morning..have an orphaned double breasted jacket where I took off the brass buttons and replaced them with regular buttons.. it was a little cooler so I also had a scarf but did not post with the pics..happy sunday guys and happy veterans day for all the active U.S Military men/women and those ofcourse that are retired!
Jacket: Polo Ralph Lauren.
Tie: Knit Tie (Gitman bros)
Pants: Suit Supply (Borrowed from a full suit)
Watch: Vintage Swiss army
Orgetorix, I really like the fit of the jacket and the jacket in general, and I think the shirt works well with it. I think the flower clashes a bit with the texture and style of the jacket, though. Also, it seems as if the top-half of the outfit is at odds with the bottom half. Without the jacket the blues would look boring but fine. With the jacket, the cuffed pants seem a bit formal and the loafers seem a little dark. Are the pants are navy (can't tell, might be dark grey?)? I would go with shoes in browns or burgundy to tie in the browns of the jacket, even though some conservative people dislike the idea of navy trousers with brown shoes. P.S., your PS looks like it's drowning.