Elli
Despite George leaving her and their newborn child, Elli decides to provide refuge to George at significant risk to herself and their child. People in similar situations would likely not do the same, especially after such a large betrayal on George's part.
Camp commandant
The commandant of the Westhofen internment camp, despite being responsible for a number of other prisoners and having limited resources, commits an extensive amount of his resources to finding and ultimately killing seven prisoners who escape. Logically, the camp commandant's actions make little sense. That's why his fixation on capturing and killing the seven escaped prisoners on crosses is ironic.
Gestapo
The Gestapo, which was created to help Hitler and his Nazi party stay in power, actually helped turn normal German citizens against the party. The people who helped George, for instance, lost faith and began to actively fight against the Nazis after unsavory encounters with the Gestapo.
Crosses
The crosses the camp commandant constructs are intensely ironic. Jesus was killed on a cross, which immediately became a profound symbol of martyrdom and for fighting for things you believe in, no matter the consequences. The camp commandant, however, doesn't care: he thinks that the crosses will serve as a warning to those who wish to escape the camp in the future.
