Notice the redesigned intake manifold in their other pictures. It's a single fuel rail setup to go in the intake manifold valley. I would imagine they are attempting to get a straighter shot on the intake port.
it's the primary fuel rail and then the secondary that holds a second set of injectors. most of nelson's cars have two fuel tanks- one for 91 oct and one for C16. so the car utilizes two sets of injectors for different boost levels.