Charts similar to that in Figure 1 are often used to illustrate the netting of exposures and simplification that central clearing can bring to an OTC market.
The tangled and highly opaque picture of a purely bilateral market is replaced by the neat hub-and-spoke network in which a CCP is buyer to every seller, and seller to every buyer, allowing netting and greater transparency for participants and regulators alike. Of course, reality is not so elegant, as Figure 2 illustrates.