Does the I/O scheduler prioritize block requests before the requests go to the generic block layer?

The sentence "The I/O scheduler provides the interface between the generic block layer and low-level physical device drivers" indicates this relationship:

Block --> I/O scheduler --> Low-level drivers

The sentence "the VM (Virtual Memory) and VFS (Virtual File System) layers submit I/O requests to block devices; it is the job of the I/O scheduling layer to prioritize and order these requests before they are given to the block devices" indicates this relationship:

VM/VFS --> I/O scheduler --> Block

So the first sentence puts the scheduler at a lower level than the block, but the second sentence puts the scheduler at a higher level than the block. Most layering schemes look like cake layers, one atop the other. In this case there's a cake layer called "block", and another layer called "scheduler" that is below and above "block". Strange cake.