The first picture is of DNA and how it supercoils. DHS, or DNAse hypersensitivity sites, arise from the coiling. They cut where there are no histones.

Similiarly, the second picture shows that if the promoters are rolled around the nucleosomes (protein that binds DNA, made of histones), they cannot be accessed. So when it’s rolled out, they are accessible, but when stored, inaccessible. Like thread on a bobbin, the DNA can be rolled out as needed to access promoters.