It shows character may be implying, rather than stating, something
She chooses to leave the building because she recognizes the futility of her effort, since she has gone, on behalf of the company representatives, to the Gestapo headquarters in order to bribe one of the officers (Karl S.) but to no avail. Since the Austrian officer "was like stone," and since she has even tried to talk to his boss, also in vain (and risking her life), she does not see other option but to leave the facility.
