I'd also say that the morphology presented in this picture is filamentous.
The reason for my believing this is that filamentous morphology concerns long visible chains, threads, or filaments, which you can see in the image.
This is because such a mechanism of regulation prevents the simultaneous addition and removal of glucose monomers, preventing unnecessary reactions. Additionally. the two processes occur in the same location in the sell, thus this regulation makes the net process more efficient. When glycogen phosphorylase is phosphorylated its activity increases and vicevarsa.