Understanding cutlass GEMM hierarchy

I think this picture is showing what cutlass is doing.

But I am not understanding what is happening. Or what is the shape?

Here they are defining several shape, why several and how it is going to work?

cutlass::gemm::GemmShape<128, 128, 64>,
cutlass::gemm::GemmShape<64, 64, 64>,
cutlass::gemm::GemmShape<16, 8, 16>,

Or here how can I relate each line to the picuture that I mentioned?


Maybe these will provide some insight.