I found Sigrid Sandström via the Little Paper Planes blog. I agree with Kelly when she says they are kind of like mind-mapping — you can see how it looks like there are incomplete parts or holes just as there are when we look back into the past. Rather than filling them with something false, the artist chooses to keep the spaces blank.
Looking closer, the shapes feel like leftover scraps from a craft project, or similar to that big board of clippings, evidence, and photos in a crime scene investigation.