About Visualizing the Convolutions and Pooling

I understand that the visualizations that we make in the notebook are the outputs after the different conv or dense layers ( 4 layers in total), according o the dimensions of the output images displayed.

however the number of layers is seven , including 2 maxpool layers and a flatten layer.

how come are we doing a loop on range(4)? is there a convetion that by default doesnt display the maxpool and flatten layers?
Thanks

Please see this topic