Has nothing to do with neckwear fashion. The scarf joint is a simpler way to join the head to the neck, than the V joint. The neck stock is cut at an angle, between 10 and 15 degrees, then one piece is flipped and glued to the other. Below, you can see the head piece ready to glue to the neck.
Below, two necks trimmed for the scarf joint. One has glue and has the pieces positioned ready to cramp.
When the pieces are roughly aligned, the cramp is added and the pieces can be jammed in.
The cramp is the perfect size for the scarf joint, leaving the gluey oozey edges clear of the cramp. The gap in the cramp is the thickness of the head without rosewood lamination.
The cramp determines the thickness. The thicker part to the left will be planed away.
Below: planing for thickness of head
Below: The side is planed square. See the joint quality.
The scarf joint, properly done is a really strong joint, a great (humble) alternative to the V joint.