This image (the verso side of Barrier Against the Wind) is scratched into wet paint to
present Ted Nakashima’s article for The New Republic in 1942. At the time Ted and
Mako (his wife) were in temporary internment at Camp Harmony, awaiting transfer
to Minidoka Internment Camp in Idaho.  Perhaps because of this writing Ted was labeled as “disloyal”. and he and Mako were later transferred to Tule Lake in northern California. Unlike internment camps Tule Lake was the Segregation Camp that confined most of the “disloyals” including No-no Boys, Nikkei, Daihyo Sho Kai leaders.
The machine gun tower in the right panel is from Tule Lake.   There were 28 guard
towers to confine over 12,000  “disloyals”  (men women &  children)  plus another
1,800 transferred from Manzanar.
For information on this see https://encyclopedia.densho.org/Tule_Lake