Depicting Trauma
Those who survived the Holocaust saw horror and suffered from enormous physical and psychological harm. Most of them starved, were sick, had to do forced labor and lived under constant stress and existential fear. Death was always very close, many lost one or more family members, some lost everyone they knew before. Many witnessed other people dying close to them. One can not image the suffering survivors had to endure.
Most survivors have to live with the trauma of their experiences for the rest of their lives. Trauma can mean many different things and it can be passed on from generation to generation.
In the graphic novel, Emmie speaks about her trauma and how she lives with it. Barbara and Emmie found ways to depict trauma in different scenes. One example is Emmie's reaction to her daughters short haircut. It triggered a memory of getting her head shaved in the concentration camp. For Emmie, short hair is "schrecklich" - horrible.
One of Emmies responses to trauma is playing solitaire on her computer. It is also a way for her to distract herself during sleepless nights.
I don't remember
Emmie doesn't remember everything. Some memories have faded over the years, as she was only a child when the Holocaust happened. Other memories might be too difficult to remember and bring up trauma.
In the graphic novel, Barbara draw not only things Emmie could remember. She also found ways of depicting things Emmie could not remember by working with empty spaces and including Emmies trauma in the story.