Huh? Air brake? If it was a groove there; that would cause an aero stagnation point. I won’t go too deep into the mechanics of what that is here – but basically; imagine that that groove causes a buildup of high pressure air in a bubble shape going forwards – now imagine that this bubble shape is part of the nose hump.
While we see nothing; basically, from an aerodynamics point of view – it’s as good as if the nose is a rounded hump (the “bubble” I spoke of has enough pressure that it doesn’t let air through itself).